The origin DNA-binding and single-stranded DNA-binding domains of simian virus 40 large T antigen are distinct.
Little is known about the ability of simian virus 40 (SV40) T antigen to bind single-stranded DNA. We demonstrate here that a mutant (259-708) missing the first 258 amino acids of T antigen and its origin-binding domain bound single-stranded DNA at close to normal levels, whereas a mutant containing only the first 259 amino acids failed to bind any single-stranded DNA. The 259-708 mutant also assembled into high-molecular-weight oligomers in the presence of single-stranded DNA. Its ATPase activity was stimulated by single-stranded DNA similarly to the wild type (WT). Furthermore, WT T antigen's ability to bind to single-stranded DNA was inhibited by the binding of two monoclonal antibodies that recognize a region after residue 362. These results show that the domain responsible for binding to single-stranded DNA is completely separate from the origin-binding domain.
Wu
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Department of Biological Sciences, University of Delaware, Newark, Delaware 19716-2590, USA.
Edgil
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Simmons
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D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000952:Antigens, Polyomavirus Transforming / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000952:Antigens, Polyomavirus Transforming; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D000251:Adenosine Triphosphatases