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1ik9
From Proteopedia
Contents |
CRYSTAL STRUCTURE OF A XRCC4-DNA LIGASE IV COMPLEX
A complex of two proteins, Xrcc4 and DNA ligase IV, plays a fundamental role in DNA non-homologous end joining (NHEJ), a cellular function required for double-strand break repair and V(D)J recombination. Here we report the crystal structure of human Xrcc4 bound to a polypeptide that corresponds to the DNA ligase IV sequence linking its two BRCA1 C-terminal (BRCT) domains. In the complex, a single ligase chain binds asymmetrically to an Xrcc4 dimer. The helical tails of Xrcc4 undergo a substantial conformational change relative to the uncomplexed protein, forming a coiled coil that unwinds upon ligase binding, leading to a flat interaction surface. A buried network of charged hydrogen bonds surrounded by extensive hydrophobic contacts explains the observed tightness of the interaction. The strong conservation of residues at the interface between the two proteins provides evidence that the observed mode of interaction has been maintained in NHEJ throughout evolution.
Crystal structure of an Xrcc4-DNA ligase IV complex., Sibanda BL, Critchlow SE, Begun J, Pei XY, Jackson SP, Blundell TL, Pellegrini L, Nat Struct Biol. 2001 Dec;8(12):1015-9. PMID:11702069
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1ik9 is a 3 chain structure of DNA ligase with sequence from Homo sapiens. The July 2004 RCSB PDB Molecule of the Month feature on DNA Ligase by David S. Goodsell is 10.2210/rcsb_pdb/mom_2004_7. Full crystallographic information is available from OCA.
See Also
Reference
- Sibanda BL, Critchlow SE, Begun J, Pei XY, Jackson SP, Blundell TL, Pellegrini L. Crystal structure of an Xrcc4-DNA ligase IV complex. Nat Struct Biol. 2001 Dec;8(12):1015-9. PMID:11702069 doi:10.1038/nsb725
