title: Identification and characterization of a mobilizing plasmid, pND300, in Lactococcus lactis M189 and its encoded nisin resistance determinant.
abstract: A 60 kb conjugative plasmid, pND300, which encodes nisin resistance, was identified in Lactococcus lactis ssp. lactis (L. lactis) M189. pND300 was found to mobilize the transfer of some other plasmids as indicated by the mobilization of plasmids encoding lactose utilization. The nisin resistance determinant from pND300 was initially subcloned on a 12 kb DNA fragment and subsequently reduced to 10.4 kb. Restriction analysis, PCR, Southern hybridization and sequencing illustrated that the nisin resistance of pND300 is very similar to that encoded by the transposon involved in nisin production. pND300 encodes nisR as well as nisK and the recently reported nisF, nisE and nisG, but does not encode nisI. The DNA fragment encoding the nis genes is flanked by IS946 with a copy at each end in reverse orientation. The expression of these nis genes is probably controlled by a putative promoter upstream of nisR, which is composed of the TTGCAA hexanucleotide on the insertion sequence IS946 and the TATAAT sequence 21 bp downstream.
authors.affiliation: Department of Biotechnology, University of New South Wales, Sydney, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Duan
authors.forename: M L
authors.initials: ML
authors.lastname: Harvey
authors.forename: C Q
authors.initials: CQ
authors.lastname: Liu
authors.forename: N W
authors.initials: NW
authors.lastname: Dunn
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000032:analysis*; D004352:Drug Resistance, Microbial / Q000235:genetics*; D013294:Lactococcus lactis / Q000187:drug effects / Q000235:genetics*; D008969:Molecular Sequence Data; D009561:Nisin / Q000494:pharmacology*; D009876:Operon; D010957:Plasmids
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D009561:Nisin