RESUMO

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.

Assuntos

Proteínas de Bactérias/genética , Bacteroides fragilis/genética , Bacteroides/genética , Biofilmes/crescimento & desenvolvimento , Liases de Carbono-Enxofre/genética , Regulação Bacteriana da Expressão Gênica , Homosserina/análogos & derivados , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Bacteroides/metabolismo , Bacteroides fragilis/metabolismo , Liases de Carbono-Enxofre/metabolismo , Sequência Conservada , Escherichia coli/genética , Escherichia coli/metabolismo , Teste de Complementação Genética , Homosserina/biossíntese , Lactonas , Dados de Sequência Molecular , Percepção de Quorum , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Transdução de Sinais