3AL2 image
Entry Detail
PDB ID:
3AL2
Title:
Crystal Structure of TopBP1 BRCT7/8
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2010-07-22
Release Date:
2010-12-01
Method Details:
Experimental Method:
Resolution:
2.00 Å
R-Value Free:
0.20
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:DNA topoisomerase 2-binding protein 1
Chain IDs:A
Chain Length:235
Number of Molecules:1
Biological Source:Homo sapiens
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
MSE A MET SELENOMETHIONINE
Ligand Molecules
Primary Citation
Molecular basis of BACH1/FANCJ recognition by TopBP1 in DNA replication checkpoint control
J.Biol.Chem. 286 4292 4301 (2011)
PMID: 21127055 DOI: 10.1074/jbc.M110.189555

Abstact

The diverse roles of TopBP1 in DNA replication and checkpoint signaling are associated with the scaffolding ability of TopBP1 to initiate various protein-protein interactions. The recognition of the BACH1/FANCJ helicase by TopBP1 is critical for the activation of the DNA replication checkpoint at stalled replication forks and is facilitated by the C-terminal tandem BRCT7/8 domains of TopBP1 and a phosphorylated Thr(1133) binding motif in BACH1. Here we provide the structural basis for this interaction through analysis of the x-ray crystal structures of TopBP1 BRCT7/8 both free and in complex with a BACH1 phospho-peptide. In contrast to canonical BRCT-phospho-peptide recognition, TopBP1 BRCT7/8 undergoes a dramatic conformational change upon BACH1 binding such that the two BRCT repeats pivot about the central BRCT-BRCT interface to provide an extensive and deep peptide-binding cleft. Additionally, we provide the first structural mechanism for Thr(P) recognition among BRCT domains. Together with systematic mutagenesis studies, we highlight the role of key contacts in governing the unique specificity of the TopBP1-BACH1 interaction.

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Primary Citation of related structures