title: Bovicin HJ50, a novel lantibiotic produced by Streptococcus bovis HJ50.
abstract: A bacteriocin-producing strain was isolated from raw milk and named Streptococcus bovis HJ50. Like most bacteriocins produced by lactic acid bacteria, bovicin HJ50 showed a narrow range of inhibiting activity. It was sensitive to trypsin, subtilisin and proteinase K. Bovicin HJ50 was extracted by n-propanol and purified by SP Sepharose Fast Flow, followed by Phenyl Superose and Sephadex G-50. Treatment of Micrococcus flavus NCIB8166 with bovicin HJ50 revealed potassium efflux from inside the cell in a concentration-dependent manner. The molecular mass of bovicin HJ50 was determined to be 3428.3 Da. MS analysis of DTT-treated bovicin HJ50 suggested that bovicin HJ50 contains a disulfide bridge. The structural gene of bovicin HJ50 was cloned by nested PCR based on its N-terminal amino acid sequence. Sequence analysis showed that it encodes a 58 aa prepeptide consisting of an N-terminal leader sequence of 25 aa and a C-terminal propeptide domain of 33 aa. Bovicin HJ50 shows similarity to type AII lantibiotics. Chemical modification using an ethanethiol-containing reaction mixture showed that two Thr residues are modified.
authors.affiliation: Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, PO Box 2714, Beijing, PR China.
authors.forename: Haijie
authors.initials: H
authors.lastname: Xiao
authors.affiliation: Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, PO Box 2714, Beijing, PR China.
authors.forename: Xiuzhu
authors.initials: X
authors.lastname: Chen
authors.affiliation: Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, PO Box 2714, Beijing, PR China.
authors.forename: Meiling
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Microbiology, University of California, Riverside, CA 92521, USA.
authors.forename: Sha
authors.initials: S
authors.lastname: Tang
authors.affiliation: Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, PO Box 2714, Beijing, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, PO Box 2714, Beijing, PR China.|Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, PO Box 2714, Beijing, PR China.
authors.forename: Liandong
authors.initials: L
authors.lastname: Huan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000187:drug effects; D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D008892:Milk / Q000382:microbiology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D016985:Streptococcus bovis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D001430:Bacteriocins; D004269:DNA, Bacterial; C000591653:bovicin HJ50, Streptococcus bovis