title: Production of AI-2 is mediated by the S-ribosylhomocystein lyase gene luxS in Bacteroides fragilis and Bacteroides vulgatus.
abstract: Quorum sensing is a cell-cell signaling mechanism based on cell density and that involves the production of hormone-like molecules called autoinducers (AI). One of the most studied AIs has been termed AI-2, and its biosynthesis requires the enzyme encoded by luxS. We have previously described for the first time that Bacteroides species can produce molecules with AI-2 activity. In this study, we focus on the detection of luxS and its activity as the AI-2 synthase in Bacteroides species. The strains Bacteroides fragilis B3b and Bacteroides vulgatus ATCC 8482 were selected based on a positive phenotype for AI-2 production and the presence of a putative luxS in the genome, respectively. In order to identify the luxS gene, cloning and heterologous expression strategies were utilized. We demonstrate that both strains contain functional luxS orthologs that can complement AI-2 production in Escherichia coli.
authors.affiliation: Departamento de Microbiologia Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Rafael José Marques
authors.initials: RJ
authors.lastname: Peixoto
authors.forename: Karla Rodrigues
authors.initials: KR
authors.lastname: Miranda
authors.forename: Eliane Oliveira
authors.initials: EO
authors.lastname: Ferreira
authors.forename: Geraldo Renato
authors.initials: GR
authors.lastname: de Paula
authors.forename: Edson Ribeiro
authors.initials: ER
authors.lastname: Rocha
authors.forename: Leandro Araujo
authors.initials: LA
authors.lastname: Lobo
authors.forename: Regina Maria Cavalcanti Pilotto
authors.initials: RM
authors.lastname: Domingues
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001439:Bacteroides / Q000235:genetics* / Q000378:metabolism; D001441:Bacteroides fragilis / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D013437:Carbon-Sulfur Lyases / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D006714:Homoserine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D007783:Lactones; D008969:Molecular Sequence Data; D053038:Quorum Sensing; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D011994:Recombinant Proteins; D006714:Homoserine; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria
keywords: Autoinducer 2; Bacteroides fragilis; Quorum sensing; luxS