Control of the transcription of a short gene encoding a cyclic peptide in Streptococcus thermophilus: a new quorum-sensing system?
| Autor: | Mariam Ibrahim, Alain Guillot, Pascal Courtin, Véronique Monnet, Florence Algaron, Rozenn Gardan, Colette Besset, Françoise Wessner |
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| Přispěvatelé: | Biochimie bactérienne (BIOBAC), Institut National de la Recherche Agronomique (INRA), Unité de recherche Biochimie et Structure des Protéines (UBSP) |
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Streptococcus thermophilus
Transcription Genetic [SDV]Life Sciences [q-bio] Mutant Peptide Genetics and Molecular Biology Oligopeptide transport Microbiology Peptides Cyclic Mass Spectrometry 03 medical and health sciences Bacterial Proteins Sequence Analysis Protein RNA Messenger Molecular Biology 030304 developmental biology 2. Zero hunger chemistry.chemical_classification Regulation of gene expression 0303 health sciences biology Edman degradation 030306 microbiology Quorum Sensing Gene Expression Regulation Bacterial biology.organism_classification Cyclic peptide Quorum sensing RNA Bacterial Biochemistry chemistry Genes Bacterial Mutation Protein Processing Post-Translational Chromatography Liquid |
| Zdroj: | Journal of Bacteriology Journal of Bacteriology, American Society for Microbiology, 2007, 189 (24), pp.8844-8854. ⟨10.1128/JB.01057-07⟩ |
| ISSN: | 0021-9193 1098-5530 |
| Popis: | Gram-positive bacteria secrete a variety of peptides that are often subjected to posttranslational modifications and that are either antimicrobials or pheromones involved in bacterial communication. Our objective was to identify peptides secreted by Streptococcus thermophilus , a nonpathogenic bacterium widely used in dairy technology in association with other bacteria, and to understand their potential roles in cell-cell communication. Using reverse-phase liquid chromatography, mass spectrometry, and Edman sequencing, we analyzed the culture supernatants of three S. thermophilus strains (CNRZ1066, LMG18311, and LMD-9) grown in a medium containing no peptides. We identified several peptides in the culture supernatants, some of them found with the three strains while others were specific to the LMD-9 strain. We focused our study on a new modified peptide secreted by S. thermophilus LMD-9 and designated Pep1357C. This peptide contains 9 amino acids and lost 2 Da in a posttranslational modification, most probably a dehydrogenation, leading to a linkage between the Lys2 and Trp6 residues. Production of Pep1357C and transcription of its encoding gene depend on both the medium composition and the growth phase. Furthermore, we demonstrated that transcription of the gene coding for Pep1357C is drastically decreased in mutants inactivated for the synthesis of a short hydrophobic peptide, a transcriptional regulator, or the oligopeptide transport system. Taken together, our results led us to deduce that the transcription of the Pep1357C-encoding gene is controlled by a new quorum-sensing system. |
| Databáze: | OpenAIRE |
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