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-Structure paper
タイトル | Structure of DNA-CMG-Pol epsilon elucidates the roles of the non-catalytic polymerase modules in the eukaryotic replisome. |
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ジャーナル・号・ページ | Nat Commun, Vol. 9, Issue 1, Page 5061, Year 2018 |
掲載日 | 2018年11月29日 |
![]() | Panchali Goswami / Ferdos Abid Ali / Max E Douglas / Julia Locke / Andrew Purkiss / Agnieszka Janska / Patrik Eickhoff / Anne Early / Andrea Nans / Alan M C Cheung / John F X Diffley / Alessandro Costa / ![]() |
PubMed 要旨 | Eukaryotic origin firing depends on assembly of the Cdc45-MCM-GINS (CMG) helicase. A key step is the recruitment of GINS that requires the leading-strand polymerase Pol epsilon, composed of Pol2, ...Eukaryotic origin firing depends on assembly of the Cdc45-MCM-GINS (CMG) helicase. A key step is the recruitment of GINS that requires the leading-strand polymerase Pol epsilon, composed of Pol2, Dpb2, Dpb3, Dpb4. While a truncation of the catalytic N-terminal Pol2 supports cell division, Dpb2 and C-terminal Pol2 (C-Pol2) are essential for viability. Dpb2 and C-Pol2 are non-catalytic modules, shown or predicted to be related to an exonuclease and DNA polymerase, respectively. Here, we present the cryo-EM structure of the isolated C-Pol2/Dpb2 heterodimer, revealing that C-Pol2 contains a DNA polymerase fold. We also present the structure of CMG/C-Pol2/Dpb2 on a DNA fork, and find that polymerase binding changes both the helicase structure and fork-junction engagement. Inter-subunit contacts that keep the helicase-polymerase complex together explain several cellular phenotypes. At least some of these contacts are preserved during Pol epsilon-dependent CMG assembly on path to origin firing, as observed with DNA replication reconstituted in vitro. |
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手法 | EM (単粒子) |
解像度 | 4.4 - 4.98 Å |
構造データ | |
化合物 | ![]() ChemComp-ZN: ![]() ChemComp-AGS: |
由来 |
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![]() | DNA BINDING PROTEIN / Polymerase epsilon / DNA replication / enzyme / DNA polymerase / Helicase / Polymerase / AAA+ protein |