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Rad52 accelerates the capture of the second 3′‐OH end in the presence of RPA
Author(s) -
Sica R. Alejandro,
Sugiyama Tomohiko,
Kowalczykowski Stephen
Publication year - 2006
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.20.5.a908-d
Subject(s) - rad52 , rad51 , replication protein a , dna , homologous recombination , rad50 , dna repair , chemistry , biophysics , non homologous end joining , holliday junction , dna damage , biology , microbiology and biotechnology , dna binding protein , biochemistry , gene , transcription factor
Double Strand breaks are the most lethal form of DNA damage. The Rad52 epistasis group of proteins (Rad50, Rad51, Rad52, Rad54, Rad55, Rad57, Rad59, Rdh54/Tid1, Mre11 and Xrs2) is involved in the repair of such lesions by means of a discrete set of reactions converting two substrates sharing homology into two recombinant products. Rad51 and Rad54 form a nucleoprotein filament with ssDNA with the capability of catalyzing homology dependent invasion of a double stranded DNA target providing the substrate for DNA polymerization. As a consequence of this displacement reaction, a single stranded DNA region is generated which will in turn be covered with RPA. The annealing of this strand with the other processed 3′‐OH end is known as second end capture, this reaction has been postulated to determine the fate of the overall recombination process. Rad52, the most essential recombination protein in S. cerevisiae , has been shown to mediate the annealing of complementary single stranded DNA bound to RPA and to be essential in double Holliday junction formation. Here, we show that Rad52 accelerates the annealing of the displaced strand to the second 3′‐OH end when covered by RPA but not the E.coli orthologue SSB. RecO, a prokaryotic annealing protein with similarities to Rad52 is not able to relieve the RPA imposed inhibition suggesting a species specific protein interaction mechanism.