title: A 37 X 10(3) molecular weight plasmid-encoded protein is required for replication and copy number control in the plasmid pSC101 and its temperature-sensitive derivative pHS1.
abstract: Nucleotide sequences were determined for a region essential for autonomous replication and partitioning of pSC101, a plasmid whose replication is dependent on the Escherichia coli dnaA gene product. The essential replication region contains one long coding sequence, rep101 , for a protein composed of 316 amino acids, and a polypeptide approximately 37 X 10(3) Mr in size was identified as the rep101 gene product. rep101 is preceded by two inverted repeat sequences, three directly repeated sequences and a region of high A + T content containing a sequence similar to the E. coli oriC consensus sequence. Because the lesions in seven replication-deficient insertion mutants, four mutants with increased copy number and one temperature-sensitive replication mutant occur within rep101 , the rep101 gene product must control pSC101 replication and copy number. par, a region adjacent to the replication region, which functions in stable plasmid inheritance, contains several inverted repeat sequences.
mesh_terms: D001345:Autoradiography; D001426:Bacterial Proteins; D001483:Base Sequence; D002874:Chromosome Mapping; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics*; D008970:Molecular Weight; D009154:Mutation; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid; D013696:Temperature
chemical_list: D001426:Bacterial Proteins