Characterization of the replication region of the small cryptic plasmid of Campylobacter hyointestinalis.
The complete nucleotide sequence of a 2.5-kb cryptic plasmid from Campylobacter hyointestinalis was determined. Only one open reading frame (ORF), encoding a polypeptide of M(r) 39,667, designated RepA, could be identified within the sequence. This was confirmed by minicell analysis. Analysis of the region upstream from the ORF showed an A+T-rich region followed by four 19-bp direct repeats. Together, these features are characteristic of other replication origins (ori(s)). The promoter sequence of the repA gene was identified by primer extension analysis and both the putative -10 and -35 regions were found to lie within two potential hairpin-loop structures. RepA showed marked amino acid sequence homology to a replication-initiation protein from the Neisseria gonorrhoeae plasmid, pFA3, and with other replication-initiation proteins over two conserved motifs. A putative partitioning (par) locus was identified upstream from the ori and consisted of a perfect 9-bp inverted repeat and six putative DNA gyrase-binding sites. A putative mobilization origin (oriT) region was identified. This featured a 19-bp imperfect inverted repeat adjacent to a sequence of 12 bp which showed strong homology to the consensus sequence of the 'nick regions' in a variety of oriTs of other plasmids.
Waterman
S R
SR
Department of Microbiology and Immunology, University of Adelaide, Australia.
Hackett
J
J
Manning
P A
PA
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002167:Campylobacter / Q000235:genetics*; D004265:DNA Helicases; D004261:DNA Replication / Q000235:genetics; D004268:DNA-Binding Proteins; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011506:Proteins; D012093:Replicon / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011506:Proteins; D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases