title: An initiator protein for plasmid R6K DNA replication. Mutations affecting the copy-number control.
abstract: Two kinds of mutations affecting the copy-number control of plasmid R6K were isolated and identified in an initiator pi protein by DNA sequencing. Firstly, a temperature-sensitive replication mutation, ts22, with decreased copy number results in a substitution of threonine to isoleucine at position 138 of the 305-amino-acid pi protein. Secondly, a high-copy-number (cop21) mutant was isolated from this ts mutant and was identified by an alteration of alanine to serine at position 162. This cop21 mutation suppressed the Ts character and was recessive to the wild-type allele in the copy control.
authors.affiliation: Department of Biochemistry, Fukui Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Inuzuka
authors.forename: Y
authors.initials: Y
authors.lastname: Wada
mesh_terms: D001483:Base Sequence; D004265:DNA Helicases; D004261:DNA Replication; D004269:DNA, Bacterial / Q000032:analysis; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010448:Peptide Initiation Factors / Q000235:genetics*; D010957:Plasmids; D013696:Temperature; D015534:Trans-Activators
chemical_list: D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D010448:Peptide Initiation Factors; D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases