3jc7
From Proteopedia
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- | '''Unreleased structure''' | ||
- | + | ==Structure of the eukaryotic replicative CMG helicase and pumpjack motion== | |
+ | <SX load='3jc7' size='340' side='right' viewer='molstar' caption='[[3jc7]], [[Resolution|resolution]] 4.80Å' scene=''> | ||
+ | == Structural highlights == | ||
+ | <table><tr><td colspan='2'>[[3jc7]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3JC7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3JC7 FirstGlance]. <br> | ||
+ | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 4.8Å</td></tr> | ||
+ | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</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=3jc7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3jc7 OCA], [https://pdbe.org/3jc7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3jc7 RCSB], [https://www.ebi.ac.uk/pdbsum/3jc7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3jc7 ProSAT]</span></td></tr> | ||
+ | </table> | ||
+ | == Function == | ||
+ | [https://www.uniprot.org/uniprot/MCM2_YEAST MCM2_YEAST] Acts as component of the MCM2-7 complex (MCM complex) which is the putative replicative helicase essential for 'once per cell cycle' DNA replication initiation and elongation in eukaryotic cells. The active ATPase sites in the MCM2-7 ring are formed through the interaction surfaces of two neighboring subunits such that a critical structure of a conserved arginine finger motif is provided in trans relative to the ATP-binding site of the Walker A box of the adjacent subunit. The six ATPase active sites, however, are likely to contribute differentially to the complex helicase activity; specifically the MCM2-MCM5 association is proposed to be reversible and to mediate a open ring conformation which may facilitate DNA loading. Once loaded onto DNA, double hexamers can slide on dsDNA in the absence of ATPase activity. Necessary for cell growth.<ref>PMID:19896182</ref> <ref>PMID:19910535</ref> | ||
+ | <div style="background-color:#fffaf0;"> | ||
+ | == Publication Abstract from PubMed == | ||
+ | The CMG helicase is composed of Cdc45, Mcm2-7 and GINS. Here we report the structure of the Saccharomyces cerevisiae CMG, determined by cryo-EM at a resolution of 3.7-4.8 A. The structure reveals that GINS and Cdc45 scaffold the N tier of the helicase while enabling motion of the AAA+ C tier. CMG exists in two alternating conformations, compact and extended, thus suggesting that the helicase moves like an inchworm. The N-terminal regions of Mcm2-7, braced by Cdc45-GINS, form a rigid platform upon which the AAA+ C domains make longitudinal motions, nodding up and down like an oil-rig pumpjack attached to a stable platform. The Mcm ring is remodeled in CMG relative to the inactive Mcm2-7 double hexamer. The Mcm5 winged-helix domain is inserted into the central channel, thus blocking entry of double-stranded DNA and supporting a steric-exclusion DNA-unwinding model. | ||
- | + | Structure of the eukaryotic replicative CMG helicase suggests a pumpjack motion for translocation.,Yuan Z, Bai L, Sun J, Georgescu R, Liu J, O'Donnell ME, Li H Nat Struct Mol Biol. 2016 Feb 8. doi: 10.1038/nsmb.3170. PMID:26854665<ref>PMID:26854665</ref> | |
- | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
- | [[Category: | + | </div> |
- | [[Category: | + | <div class="pdbe-citations 3jc7" style="background-color:#fffaf0;"></div> |
- | [[Category: | + | == References == |
- | [[Category: | + | <references/> |
- | [[Category: | + | __TOC__ |
- | [[Category: | + | </SX> |
- | [[Category: | + | [[Category: Large Structures]] |
- | [[Category: | + | [[Category: Saccharomyces cerevisiae]] |
+ | [[Category: Bai L]] | ||
+ | [[Category: Georgescu RE]] | ||
+ | [[Category: Li H]] | ||
+ | [[Category: Liu J]] | ||
+ | [[Category: O'Donnell ME]] | ||
+ | [[Category: Sun J]] | ||
+ | [[Category: Yuan Z]] |
Current revision
Structure of the eukaryotic replicative CMG helicase and pumpjack motion
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Categories: Large Structures | Saccharomyces cerevisiae | Bai L | Georgescu RE | Li H | Liu J | O'Donnell ME | Sun J | Yuan Z