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Structural mechanism of DNA replication

DNA复制的结构机制

基本信息

批准号：
10786193
负责人：
Huilin Li
金额：
$ 22.1万
依托单位：
VAN ANDEL RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-06-07 至 2024-05-31
项目状态：
已结题

项目摘要

Project Summary It is generally thought that DNA replication evolved twice, independently in Bacteria and in Archaea/Eukarya, because the principal components of the replication machinery (such as the replicative helicase and the DNA polymerases) are not evolutionarily related in the two branches of life. In mammals, chromosome replication error, or insufficient correction of a replication error, is a major cause of cancers. Initiation of DNA replication occurs in G1 phase of the cell cycle, when the replication initiator Cdc6 binds and activates the origin recognition complex (ORC) to recruit Cdt1-bound Mcm2-7 hexamer, thereby assembling an inactive Mcm2-7 double hexamer on double-stranded DNA. The molecular mechanism of this multistep initiation process is not well understood. During G1-to-S transition, the Mcm2-7 double hexamer is converted to two active replicative helicases, the Cdc45-Mcm2-7-GINS (CMG) complexes. To synthesize DNA, the primases and polymerases and over a dozen additional protein factors assemble around the CMG helicase to form the replisome progression complex (RPC). Because of its sheer size and dynamic nature, very little is known about the eukaryotic replisome architecture. However, recent advances in cryo-EM methodology, along with the most recent and spectacular success in in vitro reconstitutions of origin activation, the leading strand and the lagging strand DNA synthesis, have made it feasible to tackle these challenges. Over the past decade, we have collaborated with experts in eukaryotic DNA replication to determine atomic models of several replication complexes, including the OCCM, which is an ORC-Cdc6-Cdt1-Mcm2-7 loading intermediate on DNA; the Mcm2-7 double-hexamer on DNA; and the CMG helicase on a forked DNA. We have shown that the leading strand polymerase epsilon binds to the C-tier motor ring, whereas the Pol alpha-primase is recruited by Ctf4 to the N-tier ring side of the CMG helicase. Therefore, the two polymerases ride on opposite sides of the helicase, resulting in a profoundly asymmetric replisome architecture. Building on these successes, the PI proposes to continue the collaborative and mechanistic study of replication origin activation and replisome architecture. The proposed research is significant because replication is central to cellular growth and because dysregulation of replication can lead to uncontrolled proliferation and tumorigenesis.

项目总结

项目成果

期刊论文数量（38）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The Saccharomyces cerevisiae Yta7 ATPase hexamer contains a unique bromodomain tier that functions in nucleosome disassembly.

酿酒酵母YTA7 ATPase Hexamer包含一个独特的溴结构域层，可在核小体拆卸中起作用。

DOI：
10.1016/j.jbc.2022.102852
发表时间：
2023-03
期刊：
JOURNAL OF BIOLOGICAL CHEMISTRY
影响因子：
4.8
作者：
Wang, Feng;Feng, Xiang;He, Qing;Li, Hua;Li, Huilin
通讯作者：
Li, Huilin

Molecular mechanisms of eukaryotic origin initiation, replication fork progression, and chromatin maintenance.

DOI：
10.1042/bcj20200065
发表时间：
2020-09-30
期刊：
The Biochemical journal
影响因子：
0
作者：
Yuan Z;Li H
通讯作者：
Li H

Cdc6-induced conformational changes in ORC bound to origin DNA revealed by cryo-electron microscopy.

DOI：
10.1016/j.str.2012.01.011
发表时间：
2012-03-07
期刊：
STRUCTURE
影响因子：
5.7
作者：
Sun, Jingchuan;Kawakami, Hironori;Zech, Juergen;Speck, Christian;Stillman, Bruce;Li, Huilin
通讯作者：
Li, Huilin

Water skating: How polymerase sliding clamps move on DNA.

DOI：
10.1111/febs.15740
发表时间：
2021-12
期刊：
The FEBS journal
影响因子：
0
作者：
Li H;Zheng F;O'Donnell M
通讯作者：
O'Donnell M

Structure of the human UBR5 E3 ubiquitin ligase.

DOI：
10.1016/j.str.2023.03.010
发表时间：
2023-05-04
期刊：
STRUCTURE
影响因子：
5.7
作者：
Wang, Feng;He, Qing;Zhan, Wenhu;Yu, Ziqi;Finkin-Groner, Efrat;Ma, Xiaojing;Lin, Gang;Li, Huilin
通讯作者：
Li, Huilin