RCSB PDB - 3AL3: Crystal Structure of TopBP1 BRCT7/8-BACH1 peptide complex (original) (raw)
Crystal Structure of TopBP1 BRCT7/8-BACH1 peptide complex
This is version 1.5 of the entry. See complete history.
Molecular basis of BACH1/FANCJ recognition by TopBP1 in DNA replication checkpoint control
[Leung, C.C.](/search?q=citation.rcsb%5Fauthors:Leung, C.C.), [Gong, Z.](/search?q=citation.rcsb%5Fauthors:Gong, Z.), [Chen, J.](/search?q=citation.rcsb%5Fauthors:Chen, J.), [Glover, J.N.](/search?q=citation.rcsb%5Fauthors:Glover, J.N.)
(2011) J Biol Chem 286: 4292-4301
PubMed Abstract:
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.
Organizational Affiliation:
Department of Biochemistry, School of Molecular and Systems Medicine, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
Macromolecule Content
- Total Structure Weight: 27.84 kDa
- Atom Count: 1,961
- Modelled Residue Count: 228
- Deposited Residue Count: 245
- Unique protein chains: 2
Find similar proteins by:
(by identity cutoff) | 3D Structure
Find similar proteins by: Sequence | 3D Structure
| Modified Residues 1 Unique | |||||
|---|---|---|---|---|---|
| ID | Chains | Type | Formula | 2D Diagram | Parent |
| TPOQuery on TPO | B | L-PEPTIDE LINKING | C4 H10 N O6 P |  |
THR |
Experimental Data & Validation
Experimental Data
- Space Group: [P 62 2 2](/search?q=symmetry.space%5Fgroup%5Fname%5FH%5FM:P 62 2 2)
Unit Cell:
| Length ( Å ) | Angle ( ˚ ) |
|---|---|
| a = 78.069 | α = 90 |
| b = 78.069 | β = 90 |
| c = 136.766 | γ = 120 |
Software Package:
| Software Name | Purpose |
|---|---|
| SCALEPACK | data scaling |
| PHASER | phasing |
| REFMAC | refinement |
| PDB_EXTRACT | data extraction |
| HKL-2000 | data collection |
| DENZO | data reduction |
| HKL-2000 | data scaling |
Revision History (Full details and data files)
- Version 1.0: 2010-12-01
Type: Initial release - Version 1.1: 2011-07-13
Changes: Version format compliance - Version 1.2: 2011-11-30
Changes: Database references - Version 1.3: 2017-10-11
Changes: Refinement description - Version 1.4: 2023-11-01
Changes: Data collection, Database references, Derived calculations, Refinement description - Version 1.5: 2024-11-13
Changes: Structure summary