A plasmid-encoded two-component regulatory system involved in copper-inducible transcription in Lactococcus lactis.
Two regulatory genes (lcoR and lcoS) were identified from a plasmid-borne lactococcal copper resistance determinant and characterized by transcriptional fusion to the promoterless chloramphenicol acetyltransferase gene (cat). RT-PCR analysis indicates that lcoR and lcoS are organized within an operon, controlling the transcription of cat in a copper-inducible manner. The amino acid sequences deduced from lcoR and lcoS show homology to the response and sensor proteins of known two-component regulatory systems. Deletion within either lcoS or both genes inactivated the copper-dependent activity, suggesting the presence of no trans-acting lcoR and lcoS homologs in the lactococcal host chromosome. The transcription start site involved in copper induction was mapped by primer extension.
Khunajakr
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Cooperative Research Centre for Food Industry Innovation, Department of Biotechnology, University of New South Wales, Sydney 2052, Australia.
Liu
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CQ
Charoenchai
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P
Dunn
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NW
D001483:Base Sequence; D003001:Cloning, Molecular; D003300:Copper / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects* / Q000235:genetics; D005798:Genes, Bacterial; D017930:Genes, Reporter; D013294:Lactococcus lactis / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D017384:Sequence Deletion / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects* / Q000235:genetics
D012333:RNA, Messenger; D003300:Copper