| 63 matches found in 28 documents. Search time: 0.003 seconds. |
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Score: 1.00 |
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| Title: A telomeric avirulence gene determines efficacy for the rice blast resistance gene Pi-ta .
| | Author: Orbach MJ Farrall L Sweigard JA Chumley FG Valent B | | Citation: V : 12 ( 11 ) P : 2019-32 Year: 2000 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11090206 Accession (PMID): 11090206 | | Abstract: Genetic mapping showed that the rice blast avirulence gene AVR-Pita is tightly linked to a telomere on chromosome 3 in the plant pathogenic fungus Magnaporthe grisea .
AVR-Pita corresponds in gene-for-gene fashion to the disease resistance ( R ) gene Pi-ta .
Analysis of spontaneous avr-pita ( - ) mutants indicated that the gene is located in a telomeric 6 . 5-kb BglII restriction fragment .
Cloning and DNA sequencing led to the identification of a candidate gene with features typical of metalloproteases .
This gene is located entirely within the most distal 1 . 5 kb of the chromosome .
When introduced into virulent rice pathogens , the cloned gene specifically confers avirulence toward rice cultivars that contain Pi-ta .
Frequent spontaneous loss of AVR-Pita appears to be the result of its telomeric location .
Diverse mutations in AVR-Pita , including point mutations , insertions , and deletions , permit the fungus to avoid triggering resistance responses mediated by Pi-ta .
A point mutation in the protease consensus sequence abolishes the AVR-Pita avirulence function . | Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: Genetic mapping showed that the rice blast avirulence gene AVR-Pita is tightly linked to a telomere on chromosome 3 in the plant pathogenic fungus Magnaporthe grisea . AVR-Pita corresponds in gene-for-gene fashion to the disease resistance ( R ) gene Pi-ta . Analysis of spontaneous avr-pita ( - ) mutants indicated that the gene is located in a telomeric 6 . 5-kb BglII restriction fragment . Cloning and DNA sequencing led to the identification of a candidate gene with features typical of metalloproteases . This gene is located entirely within the most distal 1 . 5 kb of the chromosome . When introduced into virulent rice pathogens , the cloned gene specifically confers avirulence toward rice cultivars that contain Pi-ta . Frequent spontaneous loss of AVR-Pita appears to be the result of its telomeric location .
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Score: 3.00 |
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| Title: Beta-glucosidase , exo-beta-glucanase and pyridoxine transglucosylase activities of rice BGlu1 .
| | Author: Opassiri R Hua Y Wara-Aswapati O Akiyama T Svasti J Esen A Ketudat Cairns JR .
| | Citation: V : 379 ( Pt 1 ) P : 125-31 Year: 2004 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub14692878 Accession (PMID): 14692878 | | Abstract: The bglu1 cDNA for a beta-glucosidase cloned from rice ( Oryza sativa L ) seedlings was expressed as a soluble and active protein in Escherichia coli and designated BGlu1 .
This enzyme hydrolysed beta-1 , 4-linked oligosaccharides with increasing catalytic efficiency ( kcat/Km ) values as the DP ( degree of polymerization ) increased from 2 to 6 .
In contrast , hydrolysis of beta-1 , 3-linked oligosaccharides decreased from DP 2 to 3 , and polymers with a DP greater than 3 were not hydrolysed .
The enzyme also hydrolysed p -nitrophenyl beta-D-glycosides and some natural glucosides but with lower catalytic efficiency than beta-linked oligosaccharides .
Pyridoxine 5-O-beta-D-glucoside was the most efficiently hydrolysed natural glycoside tested .
BGlu1 also had high transglucosylation activity towards pyridoxine , producing pyridoxine 5-O-beta-D-glucopyranoside in the presence of the glucose donor p-nitrophenyl beta-D-glucoside . | Matching Sentences:
[ Sen. 1, subscore: 2.00 ]: The bglu1 cDNA for a beta-glucosidase cloned from rice ( Oryza sativa L ) seedlings was expressed as a soluble and active protein in Escherichia coli and designated BGlu1 . This enzyme hydrolysed beta-1 , 4-linked oligosaccharides with increasing catalytic efficiency ( kcat/Km ) values as the DP ( degree of polymerization ) increased from 2 to 6 . In contrast , hydrolysis of beta-1 , 3-linked oligosaccharides decreased from DP 2 to 3 , and polymers with a DP greater than 3 were not hydrolysed . The enzyme also hydrolysed p -nitrophenyl beta-D-glycosides and some natural glucosides but with lower catalytic efficiency than beta-linked oligosaccharides . Pyridoxine 5-O-beta-D-glucoside was the most efficiently hydrolysed natural glycoside tested .
[ Sen. 6, subscore: 1.00 ]: This enzyme hydrolysed beta-1 , 4-linked oligosaccharides with increasing catalytic efficiency ( kcat/Km ) values as the DP ( degree of polymerization ) increased from 2 to 6 . In contrast , hydrolysis of beta-1 , 3-linked oligosaccharides decreased from DP 2 to 3 , and polymers with a DP greater than 3 were not hydrolysed . The enzyme also hydrolysed p -nitrophenyl beta-D-glycosides and some natural glucosides but with lower catalytic efficiency than beta-linked oligosaccharides . Pyridoxine 5-O-beta-D-glucoside was the most efficiently hydrolysed natural glycoside tested . BGlu1 also had high transglucosylation activity towards pyridoxine , producing pyridoxine 5-O-beta-D-glucopyranoside in the presence of the glucose donor p-nitrophenyl beta-D-glucoside .
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Score: 4.00 |
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| Title: Purification , crystallization and preliminary X-ray analysis of rice BGlu1 beta-glucosidase with and without 2-deoxy-2-fluoro-beta-D-glucoside .
| | Author: Chuenchor W Pengthaisong S Yuvaniyama J Opassiri R Svasti J Ketudat Cairns JR .
| | Citation: V : 62 ( Pt 8 ) P : 798-801 Year: 2006 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub16880561 Accession (PMID): 16880561 | | Abstract: Rice ( Oryza sativa ) BGlu1 beta-glucosidase was expressed in Escherichia coli with N-terminal thioredoxin and hexahistidine tags and purified by immobilized metal-affinity chromatography ( IMAC ) .
After removal of the N-terminal tags , cation-exchange and S-200 gel-filtration chromatography yielded a 50 kDa BGlu1 with >95% purity .
The free enzyme and a complex with 2 , 4-dinitrophenyl-2-deoxy-2-fluoro-beta-D-glucopyranoside inhibitor were crystallized by microbatch and hanging-drop vapour diffusion .
Small tetragonal crystals of BGlu1 with and without inhibitor grew in 18% ( w/v ) PEG 8000 with 0 . 1 M sodium cacodylate pH 6 . 5 and 0 . 2 M zinc acetate .
Crystals of BGlu1 with inhibitor were streak-seeded into 23% ( w/v ) PEG MME 5000 , 0 . 2 M ammonium sulfate , 0 . 1 M MES pH 6 . 7 to yield larger crystals .
Crystals with and without inhibitor diffracted to 2 . 15 and 2 . 75 angstroms resolution , respectively , and had isomorphous orthorhombic unit cells belonging to space group P2 ( 1 ) 2 ( 1 ) 2 ( 1 ) . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Rice ( Oryza sativa ) BGlu1 beta-glucosidase was expressed in Escherichia coli with N-terminal thioredoxin and hexahistidine tags and purified by immobilized metal-affinity chromatography ( IMAC ) . After removal of the N-terminal tags , cation-exchange and S-200 gel-filtration chromatography yielded a 50 kDa BGlu1 with >95% purity . The free enzyme and a complex with 2 , 4-dinitrophenyl-2-deoxy-2-fluoro-beta-D-glucopyranoside inhibitor were crystallized by microbatch and hanging-drop vapour diffusion . Small tetragonal crystals of BGlu1 with and without inhibitor grew in 18% ( w/v ) PEG 8000 with 0 . 1 M sodium cacodylate pH 6 . 5 and 0 . 2 M zinc acetate . Crystals of BGlu1 with inhibitor were streak-seeded into 23% ( w/v ) PEG MME 5000 , 0 . 2 M ammonium sulfate , 0 . 1 M MES pH 6 . 7 to yield larger crystals .
[ Sen. 2, subscore: 1.00 ]: Rice ( Oryza sativa ) BGlu1 beta-glucosidase was expressed in Escherichia coli with N-terminal thioredoxin and hexahistidine tags and purified by immobilized metal-affinity chromatography ( IMAC ) . After removal of the N-terminal tags , cation-exchange and S-200 gel-filtration chromatography yielded a 50 kDa BGlu1 with >95% purity . The free enzyme and a complex with 2 , 4-dinitrophenyl-2-deoxy-2-fluoro-beta-D-glucopyranoside inhibitor were crystallized by microbatch and hanging-drop vapour diffusion . Small tetragonal crystals of BGlu1 with and without inhibitor grew in 18% ( w/v ) PEG 8000 with 0 . 1 M sodium cacodylate pH 6 . 5 and 0 . 2 M zinc acetate . Crystals of BGlu1 with inhibitor were streak-seeded into 23% ( w/v ) PEG MME 5000 , 0 . 2 M ammonium sulfate , 0 . 1 M MES pH 6 . 7 to yield larger crystals . Crystals with and without inhibitor diffracted to 2 . 15 and 2 . 75 angstroms resolution , respectively , and had isomorphous orthorhombic unit cells belonging to space group P2 ( 1 ) 2 ( 1 ) 2 ( 1 ) .
[ Sen. 4, subscore: 1.00 ]: Rice ( Oryza sativa ) BGlu1 beta-glucosidase was expressed in Escherichia coli with N-terminal thioredoxin and hexahistidine tags and purified by immobilized metal-affinity chromatography ( IMAC ) . After removal of the N-terminal tags , cation-exchange and S-200 gel-filtration chromatography yielded a 50 kDa BGlu1 with >95% purity . The free enzyme and a complex with 2 , 4-dinitrophenyl-2-deoxy-2-fluoro-beta-D-glucopyranoside inhibitor were crystallized by microbatch and hanging-drop vapour diffusion . Small tetragonal crystals of BGlu1 with and without inhibitor grew in 18% ( w/v ) PEG 8000 with 0 . 1 M sodium cacodylate pH 6 . 5 and 0 . 2 M zinc acetate . Crystals of BGlu1 with inhibitor were streak-seeded into 23% ( w/v ) PEG MME 5000 , 0 . 2 M ammonium sulfate , 0 . 1 M MES pH 6 . 7 to yield larger crystals . Crystals with and without inhibitor diffracted to 2 . 15 and 2 . 75 angstroms resolution , respectively , and had isomorphous orthorhombic unit cells belonging to space group P2 ( 1 ) 2 ( 1 ) 2 ( 1 ) .
[ Sen. 5, subscore: 1.00 ]: Rice ( Oryza sativa ) BGlu1 beta-glucosidase was expressed in Escherichia coli with N-terminal thioredoxin and hexahistidine tags and purified by immobilized metal-affinity chromatography ( IMAC ) . After removal of the N-terminal tags , cation-exchange and S-200 gel-filtration chromatography yielded a 50 kDa BGlu1 with >95% purity . The free enzyme and a complex with 2 , 4-dinitrophenyl-2-deoxy-2-fluoro-beta-D-glucopyranoside inhibitor were crystallized by microbatch and hanging-drop vapour diffusion . Small tetragonal crystals of BGlu1 with and without inhibitor grew in 18% ( w/v ) PEG 8000 with 0 . 1 M sodium cacodylate pH 6 . 5 and 0 . 2 M zinc acetate . Crystals of BGlu1 with inhibitor were streak-seeded into 23% ( w/v ) PEG MME 5000 , 0 . 2 M ammonium sulfate , 0 . 1 M MES pH 6 . 7 to yield larger crystals . Crystals with and without inhibitor diffracted to 2 . 15 and 2 . 75 angstroms resolution , respectively , and had isomorphous orthorhombic unit cells belonging to space group P2 ( 1 ) 2 ( 1 ) 2 ( 1 ) .
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Score: 4.00 |
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| Title: Enzymatic synthesis of cello-oligosaccharides by rice BGlu1 { beta } -glucosidase glycosynthase mutants .
| | Author: Hommalai G Withers SG Chuenchor W Cairns JR Svasti J | | Citation: V : ( ) P : Year: 2007 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub17405771 Accession (PMID): 17405771 | | Abstract: Rice ( BGlu1 ) beta-glucosidase is a glycosyl hydrolase family 1 enzyme that acts as an exoglucanase on beta- ( 1 , 4 ) - and short beta- ( 1 , 3 ) -linked gluco-oligosaccharides .
Mutations of BGlu1 beta-glucosidase at glutamate residue 414 of its natural precursor destroyed the enzymes catalytic activity , but the enzyme could be rescued in the presence of the anionic nucleophiles formate and azide , which verifies that this residue is the catalytic nucleophile .
The catalytic activities of three candidate mutants , E414G , E414S , and E414A , in the presence of the nucleophiles were compared .
The E414G mutant had approximately 25 and 1400-fold higher catalytic efficiency than E414A and E414S , respectively .
All three mutants could catalyze the synthesis of mixed length oligosaccharides by transglucosylation , when alpha-glucosyl fluoride was used as donor and pNP-cellobioside as acceptor .
The E414G mutant gave the fastest transglucosylation rate , which was approximately 3 and 19 fold faster than E414S and E414A , respectively , and gave yields of up to 70-80 % insoluble products with a donor : acceptor ratio of 5 : 1 .
( 13 ) C-NMR , methylation analysis and electrospray ionization mass spectrometry showed that the insoluble products were beta- ( 1 , 4 ) -linked oligomers with a degree of polymerization ( DP ) of 5 to at least 11 .
The BGlu1 E414G glycosynthase was found to prefer longer chain length oligosaccharides that occupy at least three sugar residue binding subsites as acceptors for productive transglucosylation .
This is the first report of a beta-glucansynthase derived from an exoglycosidase that can produce long chain cello-oligosaccharides , which likely reflects the extended oligosaccharide binding site of rice BGlu1 beta-glucosidase .
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[ Sen. 1, subscore: 1.00 ]: Rice ( BGlu1 ) beta-glucosidase is a glycosyl hydrolase family 1 enzyme that acts as an exoglucanase on beta- ( 1 , 4 ) - and short beta- ( 1 , 3 ) -linked gluco-oligosaccharides . Mutations of BGlu1 beta-glucosidase at glutamate residue 414 of its natural precursor destroyed the enzymes catalytic activity , but the enzyme could be rescued in the presence of the anionic nucleophiles formate and azide , which verifies that this residue is the catalytic nucleophile . The catalytic activities of three candidate mutants , E414G , E414S , and E414A , in the presence of the nucleophiles were compared . The E414G mutant had approximately 25 and 1400-fold higher catalytic efficiency than E414A and E414S , respectively . All three mutants could catalyze the synthesis of mixed length oligosaccharides by transglucosylation , when alpha-glucosyl fluoride was used as donor and pNP-cellobioside as acceptor .
[ Sen. 2, subscore: 1.00 ]: Rice ( BGlu1 ) beta-glucosidase is a glycosyl hydrolase family 1 enzyme that acts as an exoglucanase on beta- ( 1 , 4 ) - and short beta- ( 1 , 3 ) -linked gluco-oligosaccharides . Mutations of BGlu1 beta-glucosidase at glutamate residue 414 of its natural precursor destroyed the enzymes catalytic activity , but the enzyme could be rescued in the presence of the anionic nucleophiles formate and azide , which verifies that this residue is the catalytic nucleophile . The catalytic activities of three candidate mutants , E414G , E414S , and E414A , in the presence of the nucleophiles were compared . The E414G mutant had approximately 25 and 1400-fold higher catalytic efficiency than E414A and E414S , respectively . All three mutants could catalyze the synthesis of mixed length oligosaccharides by transglucosylation , when alpha-glucosyl fluoride was used as donor and pNP-cellobioside as acceptor . The E414G mutant gave the fastest transglucosylation rate , which was approximately 3 and 19 fold faster than E414S and E414A , respectively , and gave yields of up to 70-80 % insoluble products with a donor : acceptor ratio of 5 : 1 .
[ Sen. 8, subscore: 1.00 ]: The E414G mutant had approximately 25 and 1400-fold higher catalytic efficiency than E414A and E414S , respectively . All three mutants could catalyze the synthesis of mixed length oligosaccharides by transglucosylation , when alpha-glucosyl fluoride was used as donor and pNP-cellobioside as acceptor . The E414G mutant gave the fastest transglucosylation rate , which was approximately 3 and 19 fold faster than E414S and E414A , respectively , and gave yields of up to 70-80 % insoluble products with a donor : acceptor ratio of 5 : 1 . ( 13 ) C-NMR , methylation analysis and electrospray ionization mass spectrometry showed that the insoluble products were beta- ( 1 , 4 ) -linked oligomers with a degree of polymerization ( DP ) of 5 to at least 11 . The BGlu1 E414G glycosynthase was found to prefer longer chain length oligosaccharides that occupy at least three sugar residue binding subsites as acceptors for productive transglucosylation . This is the first report of a beta-glucansynthase derived from an exoglycosidase that can produce long chain cello-oligosaccharides , which likely reflects the extended oligosaccharide binding site of rice BGlu1 beta-glucosidase .
[ Sen. 9, subscore: 1.00 ]: All three mutants could catalyze the synthesis of mixed length oligosaccharides by transglucosylation , when alpha-glucosyl fluoride was used as donor and pNP-cellobioside as acceptor . The E414G mutant gave the fastest transglucosylation rate , which was approximately 3 and 19 fold faster than E414S and E414A , respectively , and gave yields of up to 70-80 % insoluble products with a donor : acceptor ratio of 5 : 1 . ( 13 ) C-NMR , methylation analysis and electrospray ionization mass spectrometry showed that the insoluble products were beta- ( 1 , 4 ) -linked oligomers with a degree of polymerization ( DP ) of 5 to at least 11 . The BGlu1 E414G glycosynthase was found to prefer longer chain length oligosaccharides that occupy at least three sugar residue binding subsites as acceptors for productive transglucosylation . This is the first report of a beta-glucansynthase derived from an exoglycosidase that can produce long chain cello-oligosaccharides , which likely reflects the extended oligosaccharide binding site of rice BGlu1 beta-glucosidase .
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Score: 3.00 |
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| Title: Structural insights into rice BGlu1 beta-glucosidase oligosaccharide hydrolysis and transglycosylation .
| | Author: Chuenchor W Pengthaisong S Robinson RC Yuvaniyama J Oonanant W Bevan DR Esen A Chen CJ Opassiri R Svasti J Cairns JR | | Citation: V : 377 P : 1200-15 Year: 2008 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub18308333 Accession (PMID): 18308333 | | Abstract: The structures of rice BGlu1 beta-glucosidase , a plant beta-glucosidase active in hydrolyzing cell wall-derived oligosaccharides , and its covalent intermediate with 2-deoxy-2-fluoroglucoside have been solved at 2 . 2 A and 1 . 55 A resolution , respectively .
The structures were similar to the known structures of other glycosyl hydrolase family 1 ( GH1 ) beta-glucosidases , but showed several differences in the loops around the active site , which lead to an open active site with a narrow slot at the bottom , compatible with the hydrolysis of long beta-1 , 4-linked oligosaccharides .
Though this active site structure is somewhat similar to that of the Paenibacillus polymyxa beta-glucosidase B , which hydrolyzes similar oligosaccharides , molecular docking studies indicate that the residues interacting with the substrate beyond the conserved -1 site are completely different , reflecting the independent evolution of plant and microbial GH1 exo-beta-glucanase/beta-glucosidases .
The complex with the 2-fluoroglucoside included a glycerol molecule , which appears to be in a position to make a nucleophilic attack on the anomeric carbon in a transglycosylation reaction .
The coordination of the hydroxyl groups suggests that sugars are positioned as acceptors for transglycosylation by their interactions with E176 , the catalytic acid/base , and Y131 , which is conserved in barley BGQ60/beta-II beta-glucosidase , that has oligosaccharide hydrolysis and transglycosylation activity similar to rice BGlu1 .
As the rice and barley enzymes have different preferences for cellobiose and cellotriose , residues that appeared to interact with docked oligosaccharides were mutated to those of the barley enzyme to see if the relative activities of rice BGlu1 toward these substrates could be changed to those of BGQ60 .
Although no single residue appeared to be responsible for these differences , I179 , N190 and N245 did appear to interact with the substrates .
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[ Sen. 1, subscore: 1.00 ]: The structures of rice BGlu1 beta-glucosidase , a plant beta-glucosidase active in hydrolyzing cell wall-derived oligosaccharides , and its covalent intermediate with 2-deoxy-2-fluoroglucoside have been solved at 2 . 2 A and 1 . 55 A resolution , respectively . The structures were similar to the known structures of other glycosyl hydrolase family 1 ( GH1 ) beta-glucosidases , but showed several differences in the loops around the active site , which lead to an open active site with a narrow slot at the bottom , compatible with the hydrolysis of long beta-1 , 4-linked oligosaccharides . Though this active site structure is somewhat similar to that of the Paenibacillus polymyxa beta-glucosidase B , which hydrolyzes similar oligosaccharides , molecular docking studies indicate that the residues interacting with the substrate beyond the conserved -1 site are completely different , reflecting the independent evolution of plant and microbial GH1 exo-beta-glucanase/beta-glucosidases . The complex with the 2-fluoroglucoside included a glycerol molecule , which appears to be in a position to make a nucleophilic attack on the anomeric carbon in a transglycosylation reaction . The coordination of the hydroxyl groups suggests that sugars are positioned as acceptors for transglycosylation by their interactions with E176 , the catalytic acid/base , and Y131 , which is conserved in barley BGQ60/beta-II beta-glucosidase , that has oligosaccharide hydrolysis and transglycosylation activity similar to rice BGlu1 .
[ Sen. 5, subscore: 1.00 ]: The structures of rice BGlu1 beta-glucosidase , a plant beta-glucosidase active in hydrolyzing cell wall-derived oligosaccharides , and its covalent intermediate with 2-deoxy-2-fluoroglucoside have been solved at 2 . 2 A and 1 . 55 A resolution , respectively . The structures were similar to the known structures of other glycosyl hydrolase family 1 ( GH1 ) beta-glucosidases , but showed several differences in the loops around the active site , which lead to an open active site with a narrow slot at the bottom , compatible with the hydrolysis of long beta-1 , 4-linked oligosaccharides . Though this active site structure is somewhat similar to that of the Paenibacillus polymyxa beta-glucosidase B , which hydrolyzes similar oligosaccharides , molecular docking studies indicate that the residues interacting with the substrate beyond the conserved -1 site are completely different , reflecting the independent evolution of plant and microbial GH1 exo-beta-glucanase/beta-glucosidases . The complex with the 2-fluoroglucoside included a glycerol molecule , which appears to be in a position to make a nucleophilic attack on the anomeric carbon in a transglycosylation reaction . The coordination of the hydroxyl groups suggests that sugars are positioned as acceptors for transglycosylation by their interactions with E176 , the catalytic acid/base , and Y131 , which is conserved in barley BGQ60/beta-II beta-glucosidase , that has oligosaccharide hydrolysis and transglycosylation activity similar to rice BGlu1 . As the rice and barley enzymes have different preferences for cellobiose and cellotriose , residues that appeared to interact with docked oligosaccharides were mutated to those of the barley enzyme to see if the relative activities of rice BGlu1 toward these substrates could be changed to those of BGQ60 . Although no single residue appeared to be responsible for these differences , I179 , N190 and N245 did appear to interact with the substrates .
[ Sen. 6, subscore: 1.00 ]: The structures were similar to the known structures of other glycosyl hydrolase family 1 ( GH1 ) beta-glucosidases , but showed several differences in the loops around the active site , which lead to an open active site with a narrow slot at the bottom , compatible with the hydrolysis of long beta-1 , 4-linked oligosaccharides . Though this active site structure is somewhat similar to that of the Paenibacillus polymyxa beta-glucosidase B , which hydrolyzes similar oligosaccharides , molecular docking studies indicate that the residues interacting with the substrate beyond the conserved -1 site are completely different , reflecting the independent evolution of plant and microbial GH1 exo-beta-glucanase/beta-glucosidases . The complex with the 2-fluoroglucoside included a glycerol molecule , which appears to be in a position to make a nucleophilic attack on the anomeric carbon in a transglycosylation reaction . The coordination of the hydroxyl groups suggests that sugars are positioned as acceptors for transglycosylation by their interactions with E176 , the catalytic acid/base , and Y131 , which is conserved in barley BGQ60/beta-II beta-glucosidase , that has oligosaccharide hydrolysis and transglycosylation activity similar to rice BGlu1 . As the rice and barley enzymes have different preferences for cellobiose and cellotriose , residues that appeared to interact with docked oligosaccharides were mutated to those of the barley enzyme to see if the relative activities of rice BGlu1 toward these substrates could be changed to those of BGQ60 . Although no single residue appeared to be responsible for these differences , I179 , N190 and N245 did appear to interact with the substrates .
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Score: 1.00 |
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| Title: A thermotolerant beta-glucosidase isolated from an endophytic fungi , Periconia sp . , with a possible use for biomass conversion to sugars .
| | Author: Harnpicharnchai P Champreda V Sornlake W Eurwilaichitr L | | Citation: V : 67 P : 61-9 .
Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub18602476 Accession (PMID): 18602476 | | Abstract: A fungal strain , BCC2871 ( Periconia sp . ) , was found to produce a thermotolerant beta-glucosidase , BGL I , with high potential for application in biomass conversion .
The full-length gene encoding the target enzyme was identified and cloned into Pichia pastoris KM71 .
Similar to the native enzyme produced by BCC2871 , the recombinant beta-glucosidase showed optimal temperature at 70 degrees C and optimal pH of 5 and 6 .
The enzyme continued to exhibit high activity even after long incubation at high temperature , retaining almost 60% of maximal activity after 1 . 5h at 70 degrees C It was also stable under basic conditions , retaining almost 100% of maximal activity after incubation for 2h at pH8 .
The enzyme has high activity towards cellobiose and other synthetic substrates containing glycosyl groups as well as cellulosic activity toward carboxymethylcellulose .
Thermostability of the enzyme was improved remarkably in the presence of cellobiose , glucose , or sucrose .
This beta-glucosidase was able to hydrolyze rice straw into simple sugars .
The addition of this beta-glucosidase to the rice straw hydrolysis reaction containing a commercial cellulase , Celluclast 1 . 5L ( Novozyme , Denmark ) resulted in increase of reducing sugars being released compared to the hydrolysis without the beta-glucosidase .
This enzyme is a candidate for applications that convert lignocellulosic biomass to biofuels and chemicals .
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[ Sen. 1, subscore: 1.00 ]: A fungal strain , BCC2871 ( Periconia sp . ) , was found to produce a thermotolerant beta-glucosidase , BGL I , with high potential for application in biomass conversion . The full-length gene encoding the target enzyme was identified and cloned into Pichia pastoris KM71 . Similar to the native enzyme produced by BCC2871 , the recombinant beta-glucosidase showed optimal temperature at 70 degrees C and optimal pH of 5 and 6 . The enzyme continued to exhibit high activity even after long incubation at high temperature , retaining almost 60% of maximal activity after 1 . 5h at 70 degrees C It was also stable under basic conditions , retaining almost 100% of maximal activity after incubation for 2h at pH8 . The enzyme has high activity towards cellobiose and other synthetic substrates containing glycosyl groups as well as cellulosic activity toward carboxymethylcellulose .
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Score: 1.00 |
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| Title: [ Screening , identifying of cellulose-decomposing strain L-06 and its enzyme-producing conditions ] | | Author: Liu Y Xuan S Long C Long M Hu Z | | Citation: V : 24 P : 1112-6 Year: 2008 Type: In-Process | | Literature: oryza Field: abstract Doc ID: pub18808002 Accession (PMID): 18808002 | | Abstract: Cellulases are relatively costly enzymes that are sold in large volumes for use in different industrial applications , and a significant reduction in cost will be important for their commercial use in biorefineries .
The production of cellulase is a major factor in the hydrolysis of cellulosic materials .
Hence it is essential to make the process economically viable .
A strain ( L-06 ) with high cellulase activity was screened from rice straw compost and classified as Penicillium decumbens by the analysis of its morphology and 18S rRNA gene sequences .
Different conditions of liquid fermentation medium including nitrogen source , carbon source , surfactant , temperature , initial pH , inoculation quantity for the production of cellulase had been studied .
The maximal beta-1 , 4-glucosidase ( BGL ) activity was 1662 u/mL which is 1 . 49 times of the previous and the maximal exo-beta-1 , 4-glucanases ( CBH ) activity was 2770 u/mL which is 1 . 36 times of the previous , cultured in the optimal condition for three days .
And the maximal endo-beta-1 , 4-glucanases ( EG ) activity was 18064 u/mL which is 1 . 87 times of the previous and the maximal filter paper enzyme ( FPase ) activity was 4035 u/mL which is 1 . 47 times of the previous , cultured in the optimal condition for four days .
In the optimization experiments , the EG and CBH in the culture condition ( pH10 ) maintained 70% and 43% activity .
In the culture condition ( 50 degrees C ) EG and CBH maintained 59% and 68% activity , which showed heat and alkali resistant characteristics .
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[ Sen. 6, subscore: 1.00 ]: The production of cellulase is a major factor in the hydrolysis of cellulosic materials . Hence it is essential to make the process economically viable . A strain ( L-06 ) with high cellulase activity was screened from rice straw compost and classified as Penicillium decumbens by the analysis of its morphology and 18S rRNA gene sequences . Different conditions of liquid fermentation medium including nitrogen source , carbon source , surfactant , temperature , initial pH , inoculation quantity for the production of cellulase had been studied . The maximal beta-1 , 4-glucosidase ( BGL ) activity was 1662 u/mL which is 1 . 49 times of the previous and the maximal exo-beta-1 , 4-glucanases ( CBH ) activity was 2770 u/mL which is 1 . 36 times of the previous , cultured in the optimal condition for three days . And the maximal endo-beta-1 , 4-glucanases ( EG ) activity was 18064 u/mL which is 1 . 87 times of the previous and the maximal filter paper enzyme ( FPase ) activity was 4035 u/mL which is 1 . 47 times of the previous , cultured in the optimal condition for four days . In the optimization experiments , the EG and CBH in the culture condition ( pH10 ) maintained 70% and 43% activity . In the culture condition ( 50 degrees C ) EG and CBH maintained 59% and 68% activity , which showed heat and alkali resistant characteristics .
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Score: 1.00 |
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| Title: Enhanced saccharification of alkali-treated rice straw by cellulase from Trametes hirsuta and statistical optimization of hydrolysis conditions by RSM .
| | Author: Jeya M Zhang YW Kim IW Lee JK | | Citation: V : 100 P : 5155-61 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19540109 Accession (PMID): 19540109 | | Abstract: A white rot fungus , identified as Trametes hirsuta based on morphological and phylogenetic analysis , was found to contain efficient cellulose degrading enzymes .
The strain showed maximum endoglucanase ( EG ) , cellobiohydrolase ( CBH ) and beta-glucosidase ( BGL ) activities of 55 , 0 . 28 and 5 . 0 U/mg-protein , respectively .
Rice straw was found to be a potentially good substrate for growth of T hirsuta for cellulase production .
Statistical experimental design was used to optimize hydrolysis parameters such as pH , temperature , and concentrations of substrates and enzymes to achieve the highest saccharification yield .
Enzyme concentration was identified as the limiting factor for saccharification of rice straw .
A maximum saccharification rate of 88% was obtained at an enzyme concentration of 37 . 5 FPU/g-substrate after optimization of the hydrolysis parameters .
The results of a confirmation experiment under the optimum conditions agreed well with model predictions .
T hirsuta may be a good choice for the production of reducing sugars from cellulosic biomass .
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[ Sen. 2, subscore: 1.00 ]: A white rot fungus , identified as Trametes hirsuta based on morphological and phylogenetic analysis , was found to contain efficient cellulose degrading enzymes . The strain showed maximum endoglucanase ( EG ) , cellobiohydrolase ( CBH ) and beta-glucosidase ( BGL ) activities of 55 , 0 . 28 and 5 . 0 U/mg-protein , respectively . Rice straw was found to be a potentially good substrate for growth of T hirsuta for cellulase production . Statistical experimental design was used to optimize hydrolysis parameters such as pH , temperature , and concentrations of substrates and enzymes to achieve the highest saccharification yield . Enzyme concentration was identified as the limiting factor for saccharification of rice straw . A maximum saccharification rate of 88% was obtained at an enzyme concentration of 37 . 5 FPU/g-substrate after optimization of the hydrolysis parameters .
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Score: 1.00 |
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| Title: Structural and enzymatic characterization of Os3BGlu6 , a rice beta-glucosidase hydrolyzing hydrophobic glycosides and ( 1->3 ) - and ( 1->2 ) -linked disaccharides .
| | Author: Seshadri S Akiyama T Opassiri R Kuaprasert B Cairns JK | | Citation: V : 151 P : 47-58 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19587102 Accession (PMID): 19587102 | | Abstract: Glycoside hydrolase family 1 ( GH1 ) beta-glucosidases play roles in many processes in plants , such as chemical defense , alkaloid metabolism , hydrolysis of cell wall-derived oligosaccharides , phytohormone regulation , and lignification .
However , the functions of most of the 34 GH1 gene products in rice ( Oryza sativa ) are unknown .
Os3BGlu6 , a rice beta-glucosidase representing a previously uncharacterized phylogenetic cluster of GH1 , was produced in recombinant Escherichia coli .
Os3BGlu6 hydrolyzed p-nitrophenyl ( pNP ) -beta-d-fucoside ( k ( cat ) /K ( m ) = 67 mm ( -1 ) s ( -1 ) ) , pNP-beta-d-glucoside ( k ( cat ) /K ( m ) = 6 . 2 mm ( -1 ) s ( -1 ) ) , and pNP-beta-d-galactoside ( k ( cat ) /K ( m ) = 1 . 6 mm ( -1 ) s ( -1 ) ) efficiently but had little activity toward other pNP glycosides .
It also had high activity toward n-octyl-beta-d-glucoside and beta- ( 1-->3 ) - and beta- ( 1-->2 ) -linked disaccharides and was able to hydrolyze apigenin beta-glucoside and several other natural glycosides .
Crystal structures of Os3BGlu6 and its complexes with a covalent intermediate , 2-deoxy-2-fluoroglucoside , and a nonhydrolyzable substrate analog , n-octyl-beta-d-thioglucopyranoside , were solved at 1 . 83 , 1 . 81 , and 1 . 80 A resolution , respectively .
The position of the covalently trapped 2-F-glucosyl residue in the enzyme was similar to that in a 2-F-glucosyl intermediate complex of Os3BGlu7 ( rice BGlu1 ) .
The side chain of methionine-251 in the mouth of the active site appeared to block the binding of extended beta- ( 1-->4 ) -linked oligosaccharides and interact with the hydrophobic aglycone of n-octyl-beta-d-thioglucopyranoside .
This correlates with the preference of Os3BGlu6 for short oligosaccharides and hydrophobic glycosides .
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[ Sen. 7, subscore: 1.00 ]: Os3BGlu6 , a rice beta-glucosidase representing a previously uncharacterized phylogenetic cluster of GH1 , was produced in recombinant Escherichia coli . Os3BGlu6 hydrolyzed p-nitrophenyl ( pNP ) -beta-d-fucoside ( k ( cat ) /K ( m ) = 67 mm ( -1 ) s ( -1 ) ) , pNP-beta-d-glucoside ( k ( cat ) /K ( m ) = 6 . 2 mm ( -1 ) s ( -1 ) ) , and pNP-beta-d-galactoside ( k ( cat ) /K ( m ) = 1 . 6 mm ( -1 ) s ( -1 ) ) efficiently but had little activity toward other pNP glycosides . It also had high activity toward n-octyl-beta-d-glucoside and beta- ( 1-->3 ) - and beta- ( 1-->2 ) -linked disaccharides and was able to hydrolyze apigenin beta-glucoside and several other natural glycosides . Crystal structures of Os3BGlu6 and its complexes with a covalent intermediate , 2-deoxy-2-fluoroglucoside , and a nonhydrolyzable substrate analog , n-octyl-beta-d-thioglucopyranoside , were solved at 1 . 83 , 1 . 81 , and 1 . 80 A resolution , respectively . The position of the covalently trapped 2-F-glucosyl residue in the enzyme was similar to that in a 2-F-glucosyl intermediate complex of Os3BGlu7 ( rice BGlu1 ) . The side chain of methionine-251 in the mouth of the active site appeared to block the binding of extended beta- ( 1-->4 ) -linked oligosaccharides and interact with the hydrophobic aglycone of n-octyl-beta-d-thioglucopyranoside . This correlates with the preference of Os3BGlu6 for short oligosaccharides and hydrophobic glycosides .
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Score: 10.00 |
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| Title: Characterization of beta-glucosidase from a strain of Penicillium purpurogenum KJS506 .
| | Author: Jeya M Joo AR Lee KM Tiwari MK Lee KM Kim SH Lee JK | | Citation: V : 86 P : 1473-84 Year: 2010 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub20043150 Accession (PMID): 20043150 | | Abstract: A novel beta-glucosidase ( BGL ) -producing strain was isolated and identified as Penicillium purpurogenum KJS506 based on its morphology and internal transcribed spacer ( ITS ) rDNA gene sequence .
When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed .
The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively .
An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources .
The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction .
The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da .
The putative gene product was identified as a member of glycoside hydrolase family 3 .
The present results should contribute to improved industrial production of BGL by P purpurogenum KJS506 .
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[ Sen. 4, subscore: 3.00 ]: A novel beta-glucosidase ( BGL ) -producing strain was isolated and identified as Penicillium purpurogenum KJS506 based on its morphology and internal transcribed spacer ( ITS ) rDNA gene sequence . When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed . The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively . An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction . The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da . The putative gene product was identified as a member of glycoside hydrolase family 3 . The present results should contribute to improved industrial production of BGL by P purpurogenum KJS506 .
[ Sen. 2, subscore: 2.00 ]: A novel beta-glucosidase ( BGL ) -producing strain was isolated and identified as Penicillium purpurogenum KJS506 based on its morphology and internal transcribed spacer ( ITS ) rDNA gene sequence . When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed . The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively . An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction . The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da .
[ Sen. 1, subscore: 1.00 ]: A novel beta-glucosidase ( BGL ) -producing strain was isolated and identified as Penicillium purpurogenum KJS506 based on its morphology and internal transcribed spacer ( ITS ) rDNA gene sequence . When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed . The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively . An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction .
[ Sen. 3, subscore: 1.00 ]: A novel beta-glucosidase ( BGL ) -producing strain was isolated and identified as Penicillium purpurogenum KJS506 based on its morphology and internal transcribed spacer ( ITS ) rDNA gene sequence . When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed . The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively . An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction . The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da . The putative gene product was identified as a member of glycoside hydrolase family 3 .
[ Sen. 5, subscore: 1.00 ]: A novel beta-glucosidase ( BGL ) -producing strain was isolated and identified as Penicillium purpurogenum KJS506 based on its morphology and internal transcribed spacer ( ITS ) rDNA gene sequence . When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed . The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively . An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction . The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da . The putative gene product was identified as a member of glycoside hydrolase family 3 . The present results should contribute to improved industrial production of BGL by P purpurogenum KJS506 .
[ Sen. 6, subscore: 1.00 ]: When rice straw and corn steep powder were used as carbon and nitrogen sources , respectively , the maximal BGL activity of 12 . 3 U ml ( -1 ) , one of the highest levels among BGL-producing microorganisms was observed . The optimum temperature and pH for BGL production were 32 degrees C and 4 , respectively . An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction . The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da . The putative gene product was identified as a member of glycoside hydrolase family 3 . The present results should contribute to improved industrial production of BGL by P purpurogenum KJS506 .
[ Sen. 8, subscore: 1.00 ]: An extracellular BGL was purified to homogeneity by sequential chromatography of P purpurogenum culture supernatants , and the purified BGL showed higher activity ( V ( max ) = 934 U mg protein ( -1 ) ) than most BGLs from other sources . The complete ORF of bgl3 was cloned from P purpurogenum by a modified thermal asymmetric interlaced polymerase chain reaction . The bgl3 gene consists of a 2 , 571-bp ORF and encodes a putative protein containing 856 amino acids with a calculated molecular mass of 89 , 624 Da . The putative gene product was identified as a member of glycoside hydrolase family 3 . The present results should contribute to improved industrial production of BGL by P purpurogenum KJS506 .
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