title: Synthesis of lactococcin 972, a bacteriocin produced by Lactococcus lactis IPLA 972, depends on the expression of a plasmid-encoded bicistronic operon.
abstract: Synthesis of lactococcin 972 is plasmid-encoded. An operon composed of two genes that encode pre-bacteriocin and a putative immunity protein has been identified. The first gene encodes a 91-residue polypeptide that is exported via a sec-dependent system to give the mature 66-aa bacteriocin. The immunity protein is a 563-residue polypeptide with seven potential transmembrane domains. Two transcripts were observed from this region: one comprises the whole operon and is synthesized during the exponential phase of growth while the other, which corresponds just to the bacteriocin structural gene, presents a maximum in exponential cultures but is still present in late-stationary-phase cells.
authors.affiliation: Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Apdo 85, 33300-Villaviciosa, Asturias, Spain1.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Martı Nez
authors.affiliation: Departamento de Biologı́a Funcional, Area de Microbiologı́a, Universidad de Oviedo, 33006-Oviedo, Spain2.
authors.forename: Marı A
authors.initials: MA
authors.lastname: Fernández
authors.affiliation: Departamento de Biologı́a Funcional, Area de Microbiologı́a, Universidad de Oviedo, 33006-Oviedo, Spain2.|Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Apdo 85, 33300-Villaviciosa, Asturias, Spain1.
authors.forename: Juan E
authors.initials: JE
authors.lastname: Suárez
authors.affiliation: Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Apdo 85, 33300-Villaviciosa, Asturias, Spain1.
authors.forename: Ana
authors.initials: A
authors.lastname: Rodrı Guez
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D013294:Lactococcus lactis / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D012329:RNA, Bacterial / Q000032:analysis; D013997:Time Factors
chemical_list: D001430:Bacteriocins; D012329:RNA, Bacterial; C402706:lactococcin 972