title: Asp-286----Asn-286 in polyomavirus large T antigen relaxes the specificity of binding to the polyomavirus origin.
abstract: We isolated revertants of a polyomavirus whose origin of DNA replication contains a point mutation in the palindrome to which large T antigen binds. Four independent second-site revertants contain an Asp-286----Asn-286 substitution in large T antigen. This mutant large T antigen activates replication of DNAs containing the mutant polyomavirus origin as well as replication of DNAs containing the wild-type origin; however, replication of DNAs with enhancer mutations is not activated by this large T antigen. The Asn-286 mutation occurs in a positively charge region of large T antigen near the location of several mutations which inactivate DNA replication. We suggest that this region of large T antigen is responsible for recognition of specific DNA sequences at the origin and that ionic forces are important for this interaction.
authors.affiliation: Department of Microbiology, University of Texas, Austin 78712-1095.
authors.forename: W J
authors.initials: WJ
authors.lastname: Tang
authors.forename: W R
authors.initials: WR
authors.lastname: Folk
mesh_terms: D000595:Amino Acid Sequence; D000952:Antigens, Polyomavirus Transforming / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D011120:Polyomavirus / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D014779:Virus Replication
chemical_list: D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral