title: Essential nucleotides in the polyomavirus origin region.
abstract: We have isolated a series of point mutants in the polyomavirus origin-intergenic control region by using a procedure which exploits the single-stranded nature of DNAs cloned into M13 phage both for the generation of mutants and for their analysis by DNA sequencing. In this report we describe the effects of cytosine X guanine----thymine X adenine base-pair substitutions in the polyomavirus origin region upon replication in mouse 3T6 cells of the M13-polyomavirus constructs. Our results indicate that sequences near the center of a 34-base-pair sequence with dyad symmetry are important for replication, whereas specific nucleotides near the ends of the dyad symmetry are not important. Furthermore, a putative large T antigen-binding site at nucleotides 60 to 80 can be mutated without affecting replication function as measured in this assay.
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D002478:Cells, Cultured; D003090:Coliphages / Q000235:genetics; D004247:DNA / Q000032:analysis*; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics; D005814:Genes, Viral; D005822:Genetic Vectors; D051379:Mice; D009154:Mutation; D011120:Polyomavirus / Q000235:genetics*; D014981:Xenopus
chemical_list: D004247:DNA; D004262:DNA Restriction Enzymes