Specificity switching of the P1 plasmid centromere-like site.
The P1 plasmid partition site acts like a centromere, promoting accurate segregation of copies to daughter cells. A 34 bp segment is essential for partition and binds the plasmid ParB protein. Additional sequences act as specificity elements that direct the choice of copies for partition. They include a second ParB binding site and a site for the host integration host factor protein. Sites lacking one or more of these additional elements are switched to a different specificity. Defined mutants were scored for partition specificity and protein binding. The results suggest that the wild-type site is folded in a specific DNA-protein complex. Disruption of the complex leads to an open configuration which, while still active in partition, has altered recognition specificity.
Davis
M A
MA
Laboratory of Chromosome Biology, NCI-Frederick Cancer Research Facility, MD 21701.
Martin
K A
KA
Austin
S J
SJ
D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism; D002503:Centromere / Q000502:physiology*; D002875:Chromosomes / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; D008961:Models, Structural; D008969:Molecular Sequence Data; D009154:Mutation; D009710:Nucleotide Mapping; D015345:Oligonucleotide Probes; D010641:Phenotype; D010957:Plasmids; D015183:Restriction Mapping
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; D015345:Oligonucleotide Probes; C440502:integration host factor, E coli