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This content will become publicly available on November 2, 2016

Title: The architecture of a eukaryotic replisome

At the eukaryotic DNA replication fork, it is widely believed that the Cdc45–Mcm2–7–GINS (CMG) helicase is positioned in front to unwind DNA and that DNA polymerases trail behind the helicase. Here we used single-particle EM to directly image a Saccharomyces cerevisiae replisome. Contrary to expectations, the leading strand Pol ε is positioned ahead of CMG helicase, whereas Ctf4 and the lagging-strand polymerase (Pol) α–primase are behind the helicase. This unexpected architecture indicates that the leading-strand DNA travels a long distance before reaching Pol ε, first threading through the Mcm2–7 ring and then making a U-turn at the bottom and reaching Pol ε at the top of CMG. Lastly, our work reveals an unexpected configuration of the eukaryotic replisome, suggests possible reasons for this architecture and provides a basis for further structural and biochemical replisome studies.
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [1] ;  [2]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States)
  2. Rockefeller Univ., New York, NY (United States)
Publication Date:
OSTI Identifier:
1257963
Report Number(s):
BNL--112308-2016-JA
Journal ID: ISSN 1545-9993
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Nature Structural & Molecular Biology
Additional Journal Information:
Journal Volume: 22; Journal Issue: 12; Journal ID: ISSN 1545-9993
Publisher:
Nature Publishing Group
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES cryoelectron microscopy; DNA