title: Copy mutant of mini-Rts1: lowered binding affinity of mutated RepA protein to direct repeats.
abstract: Nucleotide sequence analysis of mini-Rts1 and its copy mutant disclosed the presence of two clusters of direct-repeat sequences flanking the coding region for the 33,000-dalton RepA protein and two base substitutions on the mini-Rts1cop1 genome (Kamio et al., J. Bacteriol. 158:307-312, 1984). On subcloning of the left cluster (incI) that is located downstream from repA, the five 24-base-pair repeats expressed a stronger incompatibility toward mini-Rts1 than did the four repeats. The right cluster (incII) that contains three 21-base-pair repeats also exhibited strong incompatibility toward mini-Rts1. By separating the two base substitutions of mini-Rts1cop1, the mutation that is responsible for the copy increase was determined to be a single base change in the RepA coding region. Both clusters of the repeats, cloned separately into the vector plasmid, showed a weaker incompatibility toward mini-Rts1cop1 than to the wild-type mini-Rts1. These findings suggest a lowered binding affinity of the mutated RepA protein to the direct repeats.
authors.forename: Y
authors.initials: Y
authors.lastname: Terawaki
authors.forename: Y
authors.initials: Y
authors.lastname: Itoh
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004265:DNA Helicases; D004926:Escherichia coli / Q000235:genetics; D009154:Mutation; D011815:R Factors; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D000251:Adenosine Triphosphatases; D004265:DNA Helicases