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| Title: Molecular cloning and characterization of a plant homologue of the origin recognition complex 1 ( ORC1 ) .
| | Author: Kimura S Ishibashi T Hatanaka M Sakakibara Y Hashimoto J Sakaguchi K | | Journal: Citation: V : 158 ( 1-2 ) P : 33-39 Year: 2000 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub10996242 Accession (PMID): 10996242 | | Abstract: By using the rice EST database , we have isolated a 2 . 8 kb cDNA , termed Oryza sativa ORC1 ( OsORC1 ) , from rice ( O sativa ) encoding a protein that shows homology with the eukaryotic ORC1 proteins .
Alignment of the OsORC1 protein sequence with the sequence of ORC1 from human and yeasts S cerevisiae and S pombe showed a high degree of sequence homology ( 38 . 7 , 32 . 9 and 35 . 0% identity , respectively ) , particularly around the C-terminal region containing the CDC-NTP domain .
Interestingly , the OsORC1 protein had an A+T hook-like motif , which was not present in the human or yeast genes .
Genomic analysis indicated that OsORC1 existed as a single copy per genome .
OsORC1 transcripts were expressed strongly in root tips and weakly in young leaves containing root apical meristem and marginal meristem , respectively .
No expression was detected in the mature leaves .
The level of OsORC1 expression was significantly reduced when cell proliferation was temporarily halted by the removal of sucrose from the growth medium .
When the growth-halted cells began to re-grow following addition of sucrose to the medium , OsORC1 was again expressed at high levels .
These results suggested that OsORC1 is required for cell proliferation .
The role of OsORC1 in plant DNA replication will be discussed . | Matching Sentences:
[ Sen. 1, subscore: 2.00 ]: By using the rice EST database , we have isolated a 2 . 8 kb cDNA , termed Oryza sativa ORC1 ( OsORC1 ) , from rice ( O sativa ) encoding a protein that shows homology with the eukaryotic ORC1 proteins .
[ Sen. 2, subscore: 1.00 ]: Alignment of the OsORC1 protein sequence with the sequence of ORC1 from human and yeasts S cerevisiae and S pombe showed a high degree of sequence homology ( 38 . 7 , 32 . 9 and 35 . 0% identity , respectively ) , particularly around the C-terminal region containing the CDC-NTP domain .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 2.00 |
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| Title: Characterization of the origin recognition complex ( ORC ) from a higher plant , rice ( Oryza sativa L ) .
| | Author: Mori Y Yamamoto T Sakaguchi N Ishibashi T Furukawa T Kadota Y Kuchitsu K Hashimoto J Kimura S Sakaguchi K | | Journal: Gene Citation: V : 353 ( 1 ) P : 23-30 Year: 2005 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub15939553 Accession (PMID): 15939553 | | Abstract: The origin recognition complex ( ORC ) protein plays a critical role in DNA replication through binding to sites ( origins ) where replication commences .
The protein is composed of six subunits ( ORC1 to 6 ) in animals and yeasts .
Our knowledge of the ORC protein in plants is , however , much less complete .
We have performed cDNA cloning and characterization of ORC subunits in rice ( Oryza sativa L cv .
Nipponbare ) in order to facilitate study of plant DNA replication mechanisms .
Our previous report provided a description of a gene , ORC1 ( OsORC1 ) , that encodes one of the protein subunits .
The present report extends this initial analysis to include the genes that encode four other rice ORC subunits , OsORC2 , 3 , 4 and 5 .
Northern hybridization analyses demonstrated the presence of abundant transcripts for all OsORC subunits in shoot apical meristems ( SAM ) and cultured cells , but not in mature leaves .
Interestingly , only OsORC5 showed high levels of expression in organs in which cell proliferation is not active , such as flag leaves , the ears and the non-tip roots .
The pattern of expression of OsORC2 also differed from other OsORC subunits .
When cell proliferation was temporarily halted for 6-10 days by removal of sucrose from the growth medium , expression of OsORC1 , OsORC3 , OsORC4 and OsORC5 was substantially reduced .
However , the level of expression of OsORC2 remained constant .
We suggest from these results that expression of OsORC1 , 3 , 4 and 5 are correlated with cell proliferation , but the expression of OsORC2 is not . | Matching Sentences:
[ Sen. 2, subscore: 1.00 ]: The protein is composed of six subunits ( ORC1 to 6 ) in animals and yeasts .
[ Sen. 6, subscore: 1.00 ]: Our previous report provided a description of a gene , ORC1 ( OsORC1 ) , that encodes one of the protein subunits .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Putative subunits of the maize origin of replication recognition complex ZmORC1-ZmORC5 .
| | Author: Witmer X Alvarez-Venegas R San-Miguel P Danilevskaya O Avramova Z | | Journal: Nucleic Acids Res .
Citation: V : 31 ( 2 ) P : 619-28 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12527770 Accession (PMID): 12527770 | | Abstract: The finding in animal species of complexes homologous to the products of six Saccharomyces cerevisiae genes , origin of replication recognition complex ( ORC ) , has suggested that ORC-related mechanisms have been conserved in all eukaryotes .
In plants , however , the only cloned putative homologs of ORC subunits are the Arabidopsis ORC2 and the rice ORC1 .
Homologs of other subunits of plant origin have not been cloned and characterized .
A striking observation was the absence from the Arabidopsis genome of an obvious candidate gene-homolog of ORC4 .
This fact raised compelling questions of whether plants , in general , and Arabidopsis , in particular , may have lost the ORC4 gene , whether ORC-homologous subunits function within a complex in plants , whether an ORC complex may form and function without an ORC4 subunit , whether a functional ( but not sequence ) protein homolog may have taken up the role of ORC4 in Arabidopsis , and whether lack of ORC4 is a plant feature , in general Here , we report the first cloned and molecularly characterized five genes coding for the maize putative homologs of ORC subunits ZmORC1 , ZmORC2 , ZmORC3 , ZmORC4 and ZmORC5 .
Their expression profiles in it issues with different cell-dividing activities are compatible with a role in DNA replication .
Based on the potential of ORC-homologous maize proteins to bind each other in yeast , we propose a model for their possible assembly within a maize ORC .
The isolation and molecular characterization of an ORC4-homologous gene from maize argues that , in its evolution , Arabidopsis may have lost the homologous ORC4 gene .
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[ Sen. 2, subscore: 1.00 ]: In plants , however , the only cloned putative homologs of ORC subunits are the Arabidopsis ORC2 and the rice ORC1 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Molecular cloning and characterization of a plant homologue of the origin recognition complex 1 ( ORC1 ) .
| | Author: Kimura S Ishibashi T Hatanaka M Sakakibara Y Hashimoto J Sakaguchi K | | Journal: Citation: V : 158 ( 1-2 ) P : 33-39 Year: 2000 Type: ARTICLE | | Literature: oryza Field: title Doc ID: pub10996242 Accession (PMID): 10996242 | | Abstract: By using the rice EST database , we have isolated a 2 . 8 kb cDNA , termed Oryza sativa ORC1 ( OsORC1 ) , from rice ( O sativa ) encoding a protein that shows homology with the eukaryotic ORC1 proteins .
Alignment of the OsORC1 protein sequence with the sequence of ORC1 from human and yeasts S cerevisiae and S pombe showed a high degree of sequence homology ( 38 . 7 , 32 . 9 and 35 . 0% identity , respectively ) , particularly around the C-terminal region containing the CDC-NTP domain .
Interestingly , the OsORC1 protein had an A+T hook-like motif , which was not present in the human or yeast genes .
Genomic analysis indicated that OsORC1 existed as a single copy per genome .
OsORC1 transcripts were expressed strongly in root tips and weakly in young leaves containing root apical meristem and marginal meristem , respectively .
No expression was detected in the mature leaves .
The level of OsORC1 expression was significantly reduced when cell proliferation was temporarily halted by the removal of sucrose from the growth medium .
When the growth-halted cells began to re-grow following addition of sucrose to the medium , OsORC1 was again expressed at high levels .
These results suggested that OsORC1 is required for cell proliferation .
The role of OsORC1 in plant DNA replication will be discussed . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Molecular cloning and characterization of a plant homologue of the origin recognition complex 1 ( ORC1 ) .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
