Plasmid pColBM-Cl139 does not encode a colicin lysis protein but contains sequences highly homologous to the D protein (resolvase) and the oriV region of the miniF plasmid.
Colicins are usually released from producing cells by so-called lysis proteins. No sequence homologous to the structurally very similar colicin lysis genes was found in the gene cluster cmi cma cbi cba, which determines the activity and immunity proteins of colicin B and M on pColBM-Cl139. Instead, the region upstream of cmi contained sequences that showed 91% homology to the structural gene of protein D (resolvase) and 75.5% homology to the rfsF sequence of the Escherichia coli miniF plasmid. It is concluded that colicins B and M are not released via the activity of lysis proteins and that the highly homologous regions encode a resolvase and its target respectively.
Thumm
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Mikrobiologie II, University, Tübingen, West Germany.
Olschläger
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Braun
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005144:F Factor; D005796:Genes; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000235:genetics*; D010957:Plasmids; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D019895:Transposases
D001426:Bacterial Proteins; D009713:Nucleotidyltransferases; D019895:Transposases