7tfl
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[7tfl]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7TFL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7TFL FirstGlance]. <br> | <table><tr><td colspan='2'>[[7tfl]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7TFL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7TFL FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=AGS:PHOSPHOTHIOPHOSPHORIC+ACID-ADENYLATE+ESTER'>AGS</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.33Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=AGS:PHOSPHOTHIOPHOSPHORIC+ACID-ADENYLATE+ESTER'>AGS</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7tfl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7tfl OCA], [https://pdbe.org/7tfl PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7tfl RCSB], [https://www.ebi.ac.uk/pdbsum/7tfl PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7tfl ProSAT]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7tfl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7tfl OCA], [https://pdbe.org/7tfl PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7tfl RCSB], [https://www.ebi.ac.uk/pdbsum/7tfl PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7tfl ProSAT]</span></td></tr> | ||
</table> | </table> | ||
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RFC uses ATP to assemble PCNA onto primed sites for replicative DNA polymerases delta and epsilon. The RFC pentamer forms a central chamber that binds 3' ss/ds DNA junctions to load PCNA onto DNA during replication. We show here five structures that identify a second DNA binding site in RFC that binds a 5' duplex. This 5' DNA site is located between the N-terminal BRCT domain and AAA+ module of the large Rfc1 subunit. Our structures reveal ideal binding to a 7-nt gap, which includes 2 bp unwound by the clamp loader. Biochemical studies show enhanced binding to 5 and 10 nt gaps, consistent with the structural results. Because both 3' and 5' ends are present at a ssDNA gap, we propose that the 5' site facilitates RFC's PCNA loading activity at a DNA damage-induced gap to recruit gap-filling polymerases. These findings are consistent with genetic studies showing that base excision repair of gaps greater than 1 base requires PCNA and involves the 5' DNA binding domain of Rfc1. We further observe that a 5' end facilitates PCNA loading at an RPA coated 30-nt gap, suggesting a potential role of the RFC 5'-DNA site in lagging strand DNA synthesis. | RFC uses ATP to assemble PCNA onto primed sites for replicative DNA polymerases delta and epsilon. The RFC pentamer forms a central chamber that binds 3' ss/ds DNA junctions to load PCNA onto DNA during replication. We show here five structures that identify a second DNA binding site in RFC that binds a 5' duplex. This 5' DNA site is located between the N-terminal BRCT domain and AAA+ module of the large Rfc1 subunit. Our structures reveal ideal binding to a 7-nt gap, which includes 2 bp unwound by the clamp loader. Biochemical studies show enhanced binding to 5 and 10 nt gaps, consistent with the structural results. Because both 3' and 5' ends are present at a ssDNA gap, we propose that the 5' site facilitates RFC's PCNA loading activity at a DNA damage-induced gap to recruit gap-filling polymerases. These findings are consistent with genetic studies showing that base excision repair of gaps greater than 1 base requires PCNA and involves the 5' DNA binding domain of Rfc1. We further observe that a 5' end facilitates PCNA loading at an RPA coated 30-nt gap, suggesting a potential role of the RFC 5'-DNA site in lagging strand DNA synthesis. | ||
| - | Cryo-EM structures reveal that RFC recognizes both the 3'- and 5'-DNA ends to load PCNA onto gaps for DNA repair.,Zheng F, Georgescu R, Yao NY, Li H, O'Donnell ME Elife. 2022 Jul 13;11 | + | Cryo-EM structures reveal that RFC recognizes both the 3'- and 5'-DNA ends to load PCNA onto gaps for DNA repair.,Zheng F, Georgescu R, Yao NY, Li H, O'Donnell ME Elife. 2022 Jul 13;11:e77469. doi: 10.7554/eLife.77469. PMID:35829698<ref>PMID:35829698</ref> |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
Current revision
Atomic model of S. cerevisiae clamp loader RFC bound to DNA
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