title: Topography of simian virus 40 A protein-DNA complexes: arrangement of pentanucleotide interaction sites at the origin of replication.
abstract: Investigation of the DNA binding properties of the simian virus 40 (SV40) A protein (large T antigen) and the hybrid adenovirus-SV40 D2 protein revealed that both viral proteins protect similar regions of SV40 DNA from digestion by DNase I or methylation by dimethyl sulfate. However, the interaction of D2 protein with DNA was more sensitive to increases of NaCl concentration than was the interaction of wild-type SV40 A protein. Dimethylsulfate footprinting identified 13 DNA pentanucleotide contact sites at the viral origin of replication. The sequences of these sites corresponded to the consensus family 5'-(G greater than T) (A greater than G)GGC-3'. The pentanucleotides were distributed in three regions of origin DNA. Region I contained three pentanucleotide contact sites arranged as direct repetitions encompassing a span of 23 base pairs. In region II, four pentanucleotides were oriented as inverted repetitions that also spanned a total of 23 base pairs. Region III had six recognition pentanucleotides arranged as direct repetitions in a space of 59 base pairs. These fundamental variations in DNA arrangement are likely to determine different patterns of protein binding in each region.
mesh_terms: D000956:Antigens, Viral / Q000032:analysis*; D000957:Antigens, Viral, Tumor; D001483:Base Sequence; D004261:DNA Replication; D004279:DNA, Viral / Q000032:analysis*; D013539:Simian virus 40 / Q000235:genetics* / Q000276:immunology; D013463:Sulfuric Acid Esters; D014764:Viral Proteins / Q000032:analysis; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D000957:Antigens, Viral, Tumor; D004279:DNA, Viral; D013463:Sulfuric Acid Esters; D014764:Viral Proteins; C007482:dimethyl sulfate