7TI8

Structure of the yeast clamp loader (Replication Factor C RFC) bound to the open sliding clamp (Proliferating Cell Nuclear Antigen PCNA)

7TI8 の概要

• エントリーDOI: 10.2210/pdb7ti8/pdb
• EMDBエントリー: 25753
• 分子名称: Replication factor C subunit 1, Replication factor C subunit 4, Replication factor C subunit 3, ... (9 entities in total)
• 機能のキーワード: sliding clamp, dna replication, aaa+, clamp loader, replication
• 由来する生物種: Saccharomyces cerevisiae (baker's yeast); 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 340486.38

構造登録者

Gaubitz, C.,Liu, X.,Pajak, J.,Stone, N.,Hayes, J.,Demo, G.,Kelch, B.A. (登録日: 2022-01-13, 公開日: 2022-02-16, 最終更新日: 2024-02-28)

主引用文献

Gaubitz, C.,Liu, X.,Pajak, J.,Stone, N.P.,Hayes, J.A.,Demo, G.,Kelch PhD, B.A.
Cryo-EM structures reveal high-resolution mechanism of a DNA polymerase sliding clamp loader.
Elife, 11:-, 2022

PubMed Abstract: Sliding clamps are ring-shaped protein complexes that are integral to the DNA replication machinery of all life. Sliding clamps are opened and installed onto DNA by clamp loader AAA+ ATPase complexes. However, how a clamp loader opens and closes the sliding clamp around DNA is still unknown. Here, we describe structures of the clamp loader Replication Factor C (RFC) bound to its cognate sliding clamp Proliferating Cell Nuclear Antigen (PCNA) en route to successful loading. RFC first binds to PCNA in a dynamic, closed conformation that blocks both ATPase activity and DNA binding. RFC then opens the PCNA ring through a large-scale 'crab-claw' expansion of both RFC and PCNA that explains how RFC prefers initial binding of PCNA over DNA. Next, the open RFC:PCNA complex binds DNA and interrogates the primer-template junction using a surprising base-flipping mechanism. Our structures indicate that initial PCNA opening and subsequent closure around DNA do not require ATP hydrolysis, but are driven by binding energy. ATP hydrolysis, which is necessary for RFC release, is triggered by interactions with both PCNA and DNA, explaining RFC's switch-like ATPase activity. Our work reveals how a AAA+ machine undergoes dramatic conformational changes for achieving binding preference and substrate remodeling.

PubMed: 35179493
DOI: 10.7554/eLife.74175

実験手法

ELECTRON MICROSCOPY (3.5 Å)