The ATPase motif in RAD51D is required for resistance to DNA interstrand crosslinking agents and interaction with RAD51C.

Publication Type	Academic Article
Authors	Gruver A, Miller K, Rajesh C, Smiraldo P, Kaliyaperumal S, Balder R, Stiles K, Albala J, Pittman D
Journal	Mutagenesis
Volume	20
Issue	6
Pagination	433-40
Date Published	10/19/2005
ISSN	0267-8357
Keywords	Adenosine Triphosphatases, Cross-Linking Reagents, DNA, DNA-Binding Proteins, Rad51 Recombinase
Abstract	Homologous recombination (HR) is a mechanism for repairing DNA interstrand crosslinks and double-strand breaks. In mammals, HR requires the activities of the RAD51 family (RAD51, RAD51B, RAD51C, RAD51D, XRCC2, XRCC3 and DMC1), each of which contains conserved ATP binding sequences (Walker Motifs A and B). RAD51D is a DNA-stimulated ATPase that interacts directly with RAD51C and XRCC2. To test the hypothesis that ATP binding and hydrolysis by RAD51D are required for the repair of interstrand crosslinks, site-directed mutations in Walker Motif A were generated, and complementation studies were performed in Rad51d-deficient mouse embryonic fibroblasts. The K113R and K113A mutants demonstrated a respective 96 and 83% decrease in repair capacity relative to wild-type. Further examination of these mutants, by yeast two-hybrid analyses, revealed an 8-fold reduction in the ability to associate with RAD51C whereas interaction with XRCC2 was retained at a level similar to the S111T control. These cell-based studies are the first evidence that ATP binding and hydrolysis by RAD51D are required for efficient HR repair of DNA interstrand crosslinks.
PubMed ID	16236763