Mutation in the plasmid pUB110 Rep protein affects termination of rolling circle replication.
We isolated a mutant of plasmid pUB110 that has the following properties in Bacillus subtilis: (i) it is toxic for recA and add cells, particularly at elevated temperature; (ii) it has a copy number threefold higher than that of the parental plasmid, and the extra copies are present as multimers; and (iii) it can efficiently complement replication of a cmp- satellite plasmid, despite being cmp+. All these properties are due to a single change in the plasmid replication protein, i.e., Gly at position 148 to Glu. These properties of the mutant Rep protein reflect a diminished ability to terminate rolling circle replication. We propose that the Rep protein may have a diminished affinity for the plasmid origin; alternatively, it may be impaired for recognition of the plasmid conformations which distinguish initiation and termination.
Bidnenko
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Laboratoire de Génétique Microbienne, Institut National de la Recherche Agronomique, Jouy en Josas, France.
Gruss
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Ehrlich
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D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004265:DNA Helicases; D004261:DNA Replication; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D017353:Gene Deletion; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000235:genetics*; D015534:Trans-Activators
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases