8OK2

Bipartite interaction of TOPBP1 with the GINS complex

8OK2 の概要

• エントリーDOI: 10.2210/pdb8ok2/pdb
• EMDBエントリー: 16916
• 分子名称: DNA replication complex GINS protein PSF1, DNA replication complex GINS protein PSF2, DNA replication complex GINS protein PSF3, ... (5 entities in total)
• 機能のキーワード: scaffold, replisome, recruitment, replication
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 147018.11

構造登録者

Day, M.,Oliver, A.W.,Pearl, L.H. (登録日: 2023-03-26, 公開日: 2024-03-13)

主引用文献

Day, M.,Tetik, B.,Parlak, M.,Almeida-Hernandez, Y.,Raschle, M.,Kaschani, F.,Siegert, H.,Marko, A.,Sanchez-Garcia, E.,Kaiser, M.,Barker, I.A.,Pearl, L.H.,Oliver, A.W.,Boos, D.
TopBP1 utilises a bipartite GINS binding mode to support genome replication.
Nat Commun, 15:1797-1797, 2024

PubMed Abstract: Activation of the replicative Mcm2-7 helicase by loading GINS and Cdc45 is crucial for replication origin firing, and as such for faithful genetic inheritance. Our biochemical and structural studies demonstrate that the helicase activator GINS interacts with TopBP1 through two separate binding surfaces, the first involving a stretch of highly conserved amino acids in the TopBP1-GINI region, the second a surface on TopBP1-BRCT4. The two surfaces bind to opposite ends of the A domain of the GINS subunit Psf1. Mutation analysis reveals that either surface is individually able to support TopBP1-GINS interaction, albeit with reduced affinity. Consistently, either surface is sufficient for replication origin firing in Xenopus egg extracts and becomes essential in the absence of the other. The TopBP1-GINS interaction appears sterically incompatible with simultaneous binding of DNA polymerase epsilon (Polε) to GINS when bound to Mcm2-7-Cdc45, although TopBP1-BRCT4 and the Polε subunit PolE2 show only partial competitivity in binding to Psf1. Our TopBP1-GINS model improves the understanding of the recently characterised metazoan pre-loading complex. It further predicts the coordination of three molecular origin firing processes, DNA polymerase epsilon arrival, TopBP1 ejection and GINS integration into Mcm2-7-Cdc45.

PubMed: 38413589
DOI: 10.1038/s41467-024-45946-0

実験手法

ELECTRON MICROSCOPY (4.1 Å)