9PER

Structure of the S. cerevisiae clamp loader Replication Factor C (RFC) with mixed nucleotide occupancy

9PER の概要

• エントリーDOI: 10.2210/pdb9per/pdb
• EMDBエントリー: 71574
• 分子名称: Replication factor C subunit 1, Replication factor C subunit 4, Replication factor C subunit 3, ... (8 entities in total)
• 機能のキーワード: aaa+ atpase, rossmann fold, complex, dna replication, replication
• 由来する生物種: Saccharomyces cerevisiae (brewer's yeast); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 250280.32

構造登録者

Pajak, J.,Kelch, B.A. (登録日: 2025-07-02, 公開日: 2025-11-12, 最終更新日: 2025-11-26)

主引用文献

Pajak, J.,Landeck, J.T.,Liu, X.,Anand, K.,Litvak, S.,Kelch, B.A.
PCNA is a nucleotide exchange factor for the clamp loader ATPase complex.
Proc.Natl.Acad.Sci.USA, 122:e2518834122-e2518834122, 2025

PubMed Abstract: All life requires loading ring-shaped sliding clamp protein complexes onto DNA. The sliding clamp loader is a conserved AAA+ ATPase that binds the sliding clamp, opens the ring, and places it onto DNA. While recent structural work on both the canonical and "alternative" clamp loaders has shed light into how these machines perform their task once, it remains unclear how clamp loaders are recycled to load multiple sliding clamps. Here, we present structures of the clamp loader Replication Factor C (RFC) in absence of sliding clamp or supplemented nucleotide. Our structures indicate that RFC holds onto ADP tightly in at least two of its four ATPase active sites, suggesting that nucleotide exchange is regulated. Our molecular dynamics simulations and biochemical data indicate that binding of the sliding clamp Proliferating Cell Nuclear Antigen (PCNA) causes rapid exchange of tightly bound ADP. Our data suggest that PCNA acts as a nucleotide exchange factor (NEF) by prying apart adjacent subunits, providing a pathway for ADP release. We propose that, by using its own substrate as a NEF, RFC excludes off-pathway states that would arise from binding DNA prior to PCNA.

PubMed: 41231947
DOI: 10.1073/pnas.2518834122

実験手法

ELECTRON MICROSCOPY (2.57 Å)