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Insights on Rad51 Function from the Structure and Properties of a Filament Interface Mutant
Author(s) -
Morrical Scott Walker,
Chen Jianhong,
Villanueva Nicolas,
Rould Mark A.
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.645.4
Subject(s) - rad51 , protein filament , homologous recombination , dna , mutant , protein subunit , biophysics , yeast , recombination , saccharomyces cerevisiae , chemistry , crystallography , biology , biochemistry , gene
Rad51 protein promotes homologous recombination in eukaryotes. Recombination activities are activated by Rad51 filament assembly on single‐stranded DNA. Previous studies of yeast Rad51 showed that His352 occupies an important position at the filament interface, where it could relay signals between subunits and active sites. Here we report the 2.5A X‐ray crystallographic structure of the H352Y mutant of yeast Rad51. Biochemical data indicate that H352Y is trapped in a high‐affinity ssDNA‐binding conformation with limited catalytic turnover. The structure of H352Y reveals a right‐handed helical filament in a high‐pitch (130Å) conformation with P6 1 symmetry. The H352Y structure closely resembles DNA‐bound structures of E. coli RecA protein. Tyrosine substitution at position 352 locks Phe187 from the adjacent subunit into a position that interferes with the gamma‐phosphate binding site of Walker A, potentially explaining the limited catalysis observed in H352Y. Comparison of Rad51 H352Y and other RecA/Rad51 structures reveals a correlation between DNA bound/unbound status and the trans/cis configuration of a conserved peptide bond near Walker B. Funded by NIH grant number P01 CA098993.