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| ==Structure of the eukaryotic replicative CMG helicase and pumpjack motion== | | ==Structure of the eukaryotic replicative CMG helicase and pumpjack motion== |
| <StructureSection load='3jc5' size='340' side='right' caption='[[3jc5]], [[Resolution|resolution]] 4.70Å' scene=''> | | <SX load='3jc5' size='340' side='right' viewer='molstar' caption='[[3jc5]], [[Resolution|resolution]] 4.70Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[3jc5]] is a 11 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3JC5 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3JC5 FirstGlance]. <br> | | <table><tr><td colspan='2'>[[3jc5]] 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=3JC5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3JC5 FirstGlance]. <br> |
| </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3jc6|3jc6]], [[3jc7|3jc7]]</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]] 4.7Å</td></tr> |
| <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA_helicase DNA helicase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.4.12 3.6.4.12] </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=3jc5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3jc5 OCA], [https://pdbe.org/3jc5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3jc5 RCSB], [https://www.ebi.ac.uk/pdbsum/3jc5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3jc5 ProSAT]</span></td></tr> |
| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3jc5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3jc5 OCA], [http://pdbe.org/3jc5 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3jc5 RCSB], [http://www.ebi.ac.uk/pdbsum/3jc5 PDBsum]</span></td></tr> | |
| </table> | | </table> |
| == Function == | | == Function == |
| [[http://www.uniprot.org/uniprot/MCM7_YEAST MCM7_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. Once loaded onto DNA, double hexamers can slide on dsDNA in the absence of ATPase activity.<ref>PMID:19896182</ref> <ref>PMID:19910535</ref> [[http://www.uniprot.org/uniprot/PSF3_YEAST PSF3_YEAST]] Functions as part of the GINS complex which plays an essential role in the initiation of DNA replication by binding to DNA replication origins and facilitating the assembly of the DNA replication machinery.[UniProtKB:P40359]<ref>PMID:12730134</ref> [[http://www.uniprot.org/uniprot/MCM4_YEAST MCM4_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. Once loaded onto DNA, double hexamers can slide on dsDNA in the absence of ATPase activity. Required for S phase execution.<ref>PMID:19896182</ref> <ref>PMID:19910535</ref> [[http://www.uniprot.org/uniprot/CDC45_YEAST CDC45_YEAST]] Required for initiation of chromosomal DNA replication. Acts at the origin of replication. Also has a role in minichromosome maintenance.<ref>PMID:8901577</ref> <ref>PMID:9001208</ref> [[http://www.uniprot.org/uniprot/PSF2_YEAST PSF2_YEAST]] Functions as part of the GINS complex which plays an essential role in the initiation of DNA replication by binding to DNA replication origins and facilitating the assembly of the DNA replication machinery.<ref>PMID:12730134</ref> [[http://www.uniprot.org/uniprot/MCM3_YEAST MCM3_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. 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> [[http://www.uniprot.org/uniprot/SLD5_YEAST SLD5_YEAST]] Required for DNA replication. Functions as part of the GINS complex which plays an essential role in the initiation of DNA replication by binding to DNA replication origins and facilitating the assembly of the DNA replication machinery.<ref>PMID:12730134</ref> [UniProtKB:P40359] [[http://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> [[http://www.uniprot.org/uniprot/MCM5_YEAST MCM5_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.<ref>PMID:19896182</ref> <ref>PMID:19910535</ref> [[http://www.uniprot.org/uniprot/PSF1_YEAST PSF1_YEAST]] Required for DNA replication. Functions as part of the GINS complex which plays an essential role in the initiation of DNA replication by binding to DNA replication origins and facilitating the assembly of the DNA replication machinery. Required for the chromatin binding of CDC45.<ref>PMID:12730134</ref> [[http://www.uniprot.org/uniprot/MCM6_YEAST MCM6_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. Once loaded onto DNA, double hexamers can slide on dsDNA in the absence of ATPase activity. Required for the entry in S phase and for cell division.<ref>PMID:19896182</ref> <ref>PMID:19910535</ref> | | [https://www.uniprot.org/uniprot/MCM5_YEAST MCM5_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.<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> |
| | </div> |
| | <div class="pdbe-citations 3jc5" style="background-color:#fffaf0;"></div> |
| == References == | | == References == |
| <references/> | | <references/> |
| __TOC__ | | __TOC__ |
| </StructureSection> | | </SX> |
| [[Category: DNA helicase]] | | [[Category: Large Structures]] |
| [[Category: Bai, L]] | | [[Category: Saccharomyces cerevisiae]] |
| [[Category: Georgescu, R E]] | | [[Category: Bai L]] |
| [[Category: Li, H]] | | [[Category: Georgescu RE]] |
| [[Category: Liu, J]] | | [[Category: Li H]] |
| [[Category: M E., O Donnell]] | | [[Category: Liu J]] |
| [[Category: Sun, J]] | | [[Category: O'Donnell ME]] |
| [[Category: Yuan, Z]] | | [[Category: Sun J]] |
| [[Category: Cmg helicase]]
| | [[Category: Yuan Z]] |
| [[Category: Cryo-em]]
| |
| [[Category: Hydrolase]]
| |