title: Bacteriocin T8, a novel class IIa sec-dependent bacteriocin produced by Enterococcus faecium T8, isolated from vaginal secretions of children infected with human immunodeficiency virus.
abstract: Enterococcus faecium T8, isolated from vaginal secretions of children with human immunodeficiency virus, produces a class IIa sec-dependent bacteriocin that is structurally different from three other class IIa sec-dependent bacteriocins, i.e., enterocin P and an enterocin P-like bacteriocin, produced by Enterococcus faecium, and bacteriocin 31, produced by Enterococcus faecalis, and from a class III bacteriocin produced by E. faecalis. The genes encoding the bacteriocin, immunity protein, mobilization protein, and relaxase nuclease are located on a 7-kb plasmid. Bacteriocin T8 has a molecular mass of 5.1 kDa based on its DNA sequence, similar to the 5.0 kDa recorded for bacteriocin 31 but larger than the 4.6 kDa reported for enterocin P. At the amino acid level, bacteriocin T8 is 69% homologous to bacteriocin 31 and 47% homologous to enterocin P. Bacteriocin T8 is active against E. faecalis isolated from patients diagnosed with vaginosis, against Lactobacillus sakei, and against a Propionibacterium sp. The peptide is heat stable (60 min at 100 degrees C) and remains active in phosphate buffer from pH 4.0 to 10.0. The mode of activity is bactericidal, as determined with E. faecalis.
authors.affiliation: Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa.
authors.forename: M
authors.initials: M
authors.lastname: De Kwaadsteniet
authors.forename: T
authors.initials: T
authors.lastname: Fraser
authors.forename: C A
authors.initials: CA
authors.lastname: Van Reenen
authors.forename: L M T
authors.initials: LM
authors.lastname: Dicks
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D001483:Base Sequence; D001826:Body Fluids / Q000382:microbiology; D002648:Child; D013293:Enterococcus faecalis / Q000187:drug effects; D016984:Enterococcus faecium / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D015658:HIV Infections / Q000821:virology; D015497:HIV-1; D006801:Humans; D007778:Lactobacillus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011424:Propionibacterium / Q000187:drug effects; D014621:Vagina / Q000378:metabolism / Q000382:microbiology
chemical_list: D001430:Bacteriocins