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Score: 2.00 |
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| Title: Identification of amino acids important for substrate specificity in sucrose transporters using gene shuffling .
| | Author: Reinders A Sun Y Karvonen KL Ward JM | | Journal: J Biol Chem Citation: V : P : Year: 2012 Type: Publisher | | Literature: oryza Field: abstract Doc ID: pub22807445 Accession (PMID): 22807445 | | Abstract: Plant sucrose transporters ( SUTs ) are H+-coupled uptake transporters .
Type I and II ( SUTs ) are phylogenetically related but have different substrate specificities .
Type I SUTs transport sucrose , maltose and a wide range of natural and synthetic alpha and beta-glucosides .
Type II SUTs are more selective for sucrose and maltose .
Here , we investigated the structural basis for this difference in substrate specificity .
We used a novel gene shuffling method called Synthetic Template Shuffling ( STS ) to introduce 62 differentially conserved amino acid residues from type I SUTs into OsSUT1 , a type II SUT from rice .
The OsSUT1 variants were tested for their ability to transport the fluorescent coumarin beta-glucoside esculin when expressed in yeast Fluorescent yeast cells were selected using fluorescence-activated cell sorting ( FACS ) .
Substitution of five amino acids present in type I SUTs in OsSUT1 was found to be sufficient to confer esculin uptake activity .
The changes clustered in two areas of the OsSUT1 protein , in the first loop and the top of TMS2 ( T80L , A86K ) and in TMS5 ( S220A , S221A , T224Y ) .
The substrate specificity of this OsSUT1 variant was almost identical to that of type I SUTs .
Corresponding changes in the sugarcane type II transporter ShSUT1 also changed substrate specificity indicating that these residues contribute to substrate specificity in type II SUTs in general | Matching Sentences:
[ Sen. 9, subscore: 2.00 ]: The changes clustered in two areas of the OsSUT1 protein , in the first loop and the top of TMS2 ( T80L , A86K ) and in TMS5 ( S220A , S221A , T224Y ) .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Efficient replication of genotype 3a and 4a HCV replicons in human hepatoma cells .
| | Author: Saeed M Scheel TK Gottwein JM Marukian S Dustin LB Bukh J Rice CM | | Journal: Antimicrob Agents Chemother Citation: V : P : Year: 2012 Type: Publisher | | Literature: oryza Field: abstract Doc ID: pub22869572 Accession (PMID): 22869572 | | Abstract: Despite recent advances in the treatment of hepatitis C , the quest for pan-genotype , effective , and well-tolerated inhibitors continues .
To facilitate these efforts , it is desirable to have in vitro replication systems for all major HCV genotypes .
However , cell culture replication systems exist for only genotypes 1a , 1b and 2a .
In this study , we generated G418-selectable subgenomic replicons for prototype strains of genotype 3a ( S52 ) and 4a ( ED43 ) .
Production of G418-resistant colonies by S52 and ED43 in Huh-7 . 5 cells required amino acid substitutions S2210I and R2882G respectively ; cell culture adaptive mutations originally reported for genotype 1b replicons .
RNA replication was confirmed by quantitative RT-PCR and detection of viral protein .
Sequencing of multiple independent replicon clones revealed the presence of additional non-synonymous mutations .
Interestingly , all potentially adaptive mutations mapped to the NS3 protein .
These mutations , when introduced back into original constructs , substantially increased colony formation efficiency .
To make these replicons useful for high-throughput screening and evaluation of antiviral compounds , they were modified to express a chimeric fusion protein of firefly luciferase and neomycin phosphotransferase to yield stable replicon-expressing cells .
Using these constructs , the inhibitory effects of IFNbeta , an NS3 protease inhibitor and an NS5B nucleoside polymerase inhibitor were readily detected by monitoring luciferase activity .
In conclusion , we have established functional replicons for HCV genotypes 3a and 4a , important new additions to the armamentarium required to develop inhibitors with a pan-genotype activity .
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[ Sen. 5, subscore: 1.00 ]: Production of G418-resistant colonies by S52 and ED43 in Huh-7 . 5 cells required amino acid substitutions S2210I and R2882G respectively ; cell culture adaptive mutations originally reported for genotype 1b replicons .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: The primary structure of two proteins from the small ribosomal subunit of rice .
| | Author: Nishi R Hashimoto H Uchimiya H Kato A | | Journal: Biochim . Biophys . Acta Citation: V : 1216 ( 1 ) P : 113-4 Year: 1993 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub8218399 Accession (PMID): 8218399 | | Abstract: We isolated two rice cDNAs which encode an open reading frame of 117 amino acids or 82 amino acids .
Their deduced amino acid sequence correspond to the ribosomal proteins ( r-protein ) .
A comparison of the amino acid sequence shows that the deduced amino acid sequence of one cDNA is homologous to the rat r-protein S20 and Xenopus r-protein S22 .
Another encoded products with a high degree of homology to the rat r-protein S21 and the yeast r-protein YS25 . | Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: A comparison of the amino acid sequence shows that the deduced amino acid sequence of one cDNA is homologous to the rat r-protein S20 and Xenopus r-protein S22 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
