2VXC: Structure Of The Crb2-Brct2 Domain Complex With Phosphopeptide

Schizosaccharomyces pombe Crb2 is a checkpoint mediator required for the cellular response to DNA damage. Like human 53BP1 and Saccharomyces cerevisiae Rad9 it contains Tudor(2) and BRCT(2) domains. Crb2-Tudor(2) domain interacts with methylated H4K20 and is required for recruitment to DNA dsDNA breaks. The BRCT(2) domain is required for dimerization, but its precise role in DNA damage repair and checkpoint signaling is unclear. The crystal structure of the Crb2-BRCT(2) domain, alone and in complex with a phosphorylated H2A.1 peptide, reveals the structural basis for dimerization and direct interaction with gamma-H2A.1 in ionizing radiation-induced foci (IRIF). Mutational analysis in vitro confirms the functional role of key residues and allows the generation of mutants in which dimerization and phosphopeptide binding are separately disrupted. Phenotypic analysis of these in vivo reveals distinct roles in the DNA damage response. Dimerization mutants are genotoxin sensitive and defective in checkpoint signaling, Chk1 phosphorylation, and Crb2 IRIF formation, while phosphopeptide-binding mutants are only slightly sensitive to IR, have extended checkpoint delays, phosphorylate Chk1, and form Crb2 IRIF. However, disrupting phosphopeptide binding slows formation of ssDNA-binding protein (Rpa1/Rad11) foci and reduces levels of Rad22(Rad52) recombination foci, indicating a DNA repair defect.
PDB ID: 2VXCDownload
MMDB ID: 65980
PDB Deposition Date: 2008/7/3
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
Homo sapiens
Similar Structures:
Biological Unit for 2VXC: trimeric; determined by author and by software (PQS)
Molecular Components in 2VXC
Label Count Molecule
Proteins (3 molecules)
DNA Repair Protein Rhp9(Gene symbol: crb2)
Molecule annotation
H2a1 Peptide
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB