3K75: X-Ray Crystal Structure Of Reduced Xrcc1 Bound To Dna Pol Beta Catalytic Domain

Formation of a complex between the XRCC1 N-terminal domain (NTD) and DNA polymerase beta (Pol beta) is central to base excision repair of damaged DNA. Two crystal forms of XRCC1-NTD complexed with Pol beta have been solved, revealing that the XRCC1-NTD is able to adopt a redox-dependent alternate fold, characterized by a disulfide bond, and substantial variations of secondary structure, folding topology, and electrostatic surface. Although most of these structural changes occur distal to the interface, the oxidized XRCC1-NTD forms additional interactions with Pol beta, enhancing affinity by an order of magnitude. Transient disulfide bond formation is increasingly recognized as an important molecular regulatory mechanism. The results presented here suggest a paradigm in DNA repair in which the redox state of a scaffolding protein plays an active role in organizing the repair complex.
PDB ID: 3K75Download
MMDB ID: 81687
PDB Deposition Date: 2009/10/12
Updated in MMDB: 2012/09
Experimental Method:
x-ray diffraction
Resolution: 2.95  Å
Source Organism:
Rattus norvegicus
Similar Structures:
Biological Unit for 3K75: dimeric; determined by author and by software (PISA)
Molecular Components in 3K75
Label Count Molecule
Proteins (2 molecules)
DNA Repair Protein Xrcc1(Gene symbol: XRCC1)
Molecule annotation
DNA Polymerase Beta(Gene symbol: Polb)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB