The human pre-replication complex is an open complex

Jian Li; Jiangqing Dong; Weitao Wang; Daqi Yu; Xinyu Fan; Yan Chit Hui; Clare S K Lee; Wai Hei Lam; Nathan Alary; Yang Yang; Yingyi Zhang; Qian Zhao; Chun-Long Chen; Bik-Kwoon Tye; Shangyu Dang; Yuanliang Zhai

doi:10.1016/j.cell.2022.12.008

The human pre-replication complex is an open complex

Cell. 2023 Jan 5;186(1):98-111.e21. doi: 10.1016/j.cell.2022.12.008.

Authors

Jian Li¹, Jiangqing Dong², Weitao Wang³, Daqi Yu², Xinyu Fan¹, Yan Chit Hui¹, Clare S K Lee¹, Wai Hei Lam¹, Nathan Alary³, Yang Yang⁴, Yingyi Zhang⁵, Qian Zhao⁴, Chun-Long Chen⁶, Bik-Kwoon Tye⁷, Shangyu Dang⁸, Yuanliang Zhai⁹

Affiliations

¹ School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
² Division of Life Science, Center of Systems Biological and Human Health, The Hong Kong University of Science and Technology, Hong Kong, China.
³ Institut Curie, PSL Research University, CNRS UMR3244, Dynamics of Genetic Information, Sorbonne Université, 75005 Paris, France.
⁴ State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hong Kong, China.
⁵ Biological Cryo-EM Center, The Hong Kong University of Science and Technology, Hong Kong, China.
⁶ Institut Curie, PSL Research University, CNRS UMR3244, Dynamics of Genetic Information, Sorbonne Université, 75005 Paris, France. Electronic address: chunlong.chen@curie.fr.
⁷ Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong, China; Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY 14853, USA. Electronic address: biktye@ust.hk.
⁸ Division of Life Science, Center of Systems Biological and Human Health, The Hong Kong University of Science and Technology, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China; HKUST-Shenzhen Research Institute, Nanshan, Shenzhen 518057, China. Electronic address: sdang@ust.hk.
⁹ School of Biological Sciences, The University of Hong Kong, Hong Kong, China. Electronic address: zhai@hku.hk.

PMID: 36608662
DOI: 10.1016/j.cell.2022.12.008

Abstract

In eukaryotes, DNA replication initiation requires assembly and activation of the minichromosome maintenance (MCM) 2-7 double hexamer (DH) to melt origin DNA strands. However, the mechanism for this initial melting is unknown. Here, we report a 2.59-Å cryo-electron microscopy structure of the human MCM-DH (hMCM-DH), also known as the pre-replication complex. In this structure, the hMCM-DH with a constricted central channel untwists and stretches the DNA strands such that almost a half turn of the bound duplex DNA is distorted with 1 base pair completely separated, generating an initial open structure (IOS) at the hexamer junction. Disturbing the IOS inhibits DH formation and replication initiation. Mapping of hMCM-DH footprints indicates that IOSs are distributed across the genome in large clusters aligning well with initiation zones designed for stochastic origin firing. This work unravels an intrinsic mechanism that couples DH formation with initial DNA melting to license replication initiation in human cells.

Keywords: DNA replication initiation; human MCM2–7 complex; initial DNA melting; origin firing; pre-RC; replication licensing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Cycle Proteins / metabolism
Cryoelectron Microscopy
DNA Replication*
DNA-Binding Proteins / metabolism
Humans
Minichromosome Maintenance Proteins / metabolism
Replication Origin

Substances

Cell Cycle Proteins
DNA-Binding Proteins
Minichromosome Maintenance Proteins