title: Characterization and distribution of the gene cluster encoding RumC, an anti-Clostridium perfringens bacteriocin produced in the gut.
abstract: Ruminococcin C (RumC) is a trypsin-dependent bacteriocin produced by Ruminococcus gnavus E1, a gram-positive strict anaerobic strain isolated from human feces. It consists of at least three similar peptides active against Clostridium perfringens. In this article, a 15-kb region from R. gnavus E1 chromosome, containing the biosynthetic gene cluster of RumC was characterized. It harbored 17 open reading frames (called rum(c) genes) with predicted functions in bacteriocin biosynthesis and post-translational modification, signal transduction regulation, and immunity. An unusual feature of the locus is the presence of five genes encoding highly homologous, but nonidentical RumC precursors. The transcription levels of the rum(c) genes were quantified. The rumC genes were found to be highly expressed in vivo, when R. gnavus E1 colonized the digestive tract of mono-contaminated rats, whereas the amount of corresponding transcripts was below detection level when it grew in liquid culture medium. Moreover, the rumC-like genes were disseminated among 10 strains (R. gnavus or related species) previously isolated from human fecal samples and selected for their capability to produce a trypsin-dependant anti-C. perfringens compound. All harbored at least a rumC1-like copy, four exhibited rumC1-5 genes identical to those of strain E1.
authors.affiliation: ISM2/BiosCiences UMR CNRS 6263, Service 342, Faculté des Sciences et Techniques de St. Jérôme, Université Paul Cézanne Aix-Marseille III, Marseille, France.
authors.forename: Ange
authors.initials: A
authors.lastname: Pujol
authors.forename: Emmanuelle H
authors.initials: EH
authors.lastname: Crost
authors.forename: Gwenola
authors.initials: G
authors.lastname: Simon
authors.forename: Valerie
authors.initials: V
authors.lastname: Barbe
authors.forename: David
authors.initials: D
authors.lastname: Vallenet
authors.forename: Ana
authors.initials: A
authors.lastname: Gomez
authors.forename: Michel
authors.initials: M
authors.lastname: Fons
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001430:Bacteriocins / Q000235:genetics* / Q000378:metabolism / Q000633:toxicity; D001483:Base Sequence; D003016:Clostridium perfringens / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D011499:Protein Processing, Post-Translational; D051381:Rats; D045857:Ruminococcus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014357:Trypsin / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D014357:Trypsin