Effect of DNA sequence and nucleotide cofactors on hRad51 binding to ssDNA: role of hRad52 in recruitment.
hRad51 binding to ssDNA is significantly lowered in the presence of a nucleotide cofactor ATP/ADP/ATPgammaS. In these conditions, presence of trace amounts of hRad52 protein restores hRad51 binding to DNA. In the absence of any nucleotide cofactor where intrinsic binding of hRad51 to ssDNA is higher, hRad52 brings about no improved binding. hRad51 binding to ssDNA is strongly influenced by the DNA sequence. The protein binding to repeat sequences is poor compared to that of mixed DNA sequence. Interestingly, presence of hRad52 restores the ability of hRad51 binding to such DNA targets as well. Moreover, all the cooperative effects of hRad52 on hRad51 binding are highly specific to the latter's binding to ssDNA and not to dsDNA. These results help us to model important mechanistic steps of hRad51 presynapsis on ssDNA templates.
Navadgi
Vasundhara M
VM
Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India.
Shukla
Ashish
A
Rao
Basuthkar J
BJ
D000244:Adenosine Diphosphate / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000737:chemistry; D051721:Rad52 DNA Repair and Recombination Protein; D013329:Structure-Activity Relationship
D004268:DNA-Binding Proteins; D009711:Nucleotides; C497194:RAD52 protein, human; D051721:Rad52 DNA Repair and Recombination Protein; C022571:adenosine 5'-O-(3-thiotriphosphate); D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D004247:DNA