Dataset Information

Regulation of Mannitol Metabolism in Enterococcus faecalis and Association with par_EF0409 Toxin-Antitoxin Locus Function.

ABSTRACT: The par_EF0409 type I toxin-antitoxin locus is situated between genes for two paralogous mannitol family phosphoenolpyruvate phosphotransferase systems (PTSs). In order to address the possibility that par_EF0409 function was associated with sugar metabolism, genetic and phenotypic analyses were performed on the flanking genes. It was found that the genes were transcribed as two operons: the downstream operon essential for mannitol transport and metabolism and the upstream operon performing a regulatory function. In addition to genes for the PTS components, the upstream operon harbors a gene similar to mtlR, the key regulator of mannitol metabolism in other Gram-positive bacteria. We confirmed that this gene is essential for the regulation of the downstream operon and identified putative phosphorylation sites required for carbon catabolite repression and mannitol-specific regulation. Genomic comparisons revealed that this dual-operon organization of mannitol utilization genes is uncommon in enterococci and that the association with a toxin-antitoxin system is unique to Enterococcus faecalis. Finally, we consider possible links between par_EF0409 function and mannitol utilization. IMPORTANCE Enterococcus faecalis is both a common member of the human gut microbiota and an opportunistic pathogen. Its evolutionary success is partially due to its metabolic flexibility, in particular its ability to import and metabolize a wide variety of sugars. While a large number of phosphoenolpyruvate phosphotransferase sugar transport systems have been identified in the E. faecalis genome bioinformatically, the specificity and regulation of most of these systems remain undetermined. Here, we characterize a complex system of two operons flanking a type I toxin-antitoxin system required for the transport and metabolism of the common dietary sugar mannitol. We also determine the phylogenetic distribution of mannitol utilization genes in the enterococcal genus and discuss the significance of the association with toxin-antitoxin systems.

SUBMITTER: Anbalagan S

PROVIDER: S-EPMC9112947 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Regulation of Mannitol Metabolism in Enterococcus faecalis and Association with parEF0409 Toxin-Antitoxin Locus Function.

Anbalagan Srivishnupriya S Sadlon Jessie J Weaver Keith K

Journal of bacteriology 20220411 5

The parEF0409 type I toxin-antitoxin locus is situated between genes for two paralogous mannitol family phosphoenolpyruvate phosphotransferase systems (PTSs). In order to address the possibility that parEF0409 function was associated with sugar metabolism, genetic and phenotypic analyses were performed on the flanking genes. It was found that the genes were transcribed as two operons: the downstream operon essential for mannitol transport and metabolism and th ...[more]

PMID: 35404112

Similar Datasets

Project description:Background & aimsThe inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis, are caused in part by aberrant immune responses to resident intestinal bacteria. Certain dietary components, including carbohydrates, are associated with IBDs and alter intestinal bacterial composition. However, the effects of luminal carbohydrates on the composition and colitogenic potential of intestinal bacteria are incompletely understood. We hypothesize that carbohydrate metabolism by resident proinflammatory intestinal bacteria enhances their growth and worsens intestinal inflammation.MethodsWe colonized germ-free, wild-type, and colitis-susceptible interleukin-10 knockout mice (Il10-/-) with a consortium of resident intestinal bacterial strains and quantified colon inflammation using blinded histologic scoring and spontaneous secretion of IL12/23p40 by colon explants. We measured luminal bacterial composition using real-time 16S polymerase chain reaction, bacterial gene expression using RNA sequencing and real-time polymerase chain reaction, and luminal glucosamine levels using gas chromatography-mass spectrometry.ResultsWe show that a consortium of 8 bacterial strains induces severe colitis in Il10-/- mice and up-regulates genes associated with carbohydrate metabolism during colitis. Specifically, Enterococcus faecalis strain OG1RF is proinflammatory and strongly up-regulates OG1RF_11616-11610, an operon that encodes genes of a previously undescribed phosphotransferase system that we show imports glucosamine. Experimental colitis is associated with increased levels of luminal glucosamine and OG1RF_11616 causes worse colitis, not by increasing E faecalis numbers, but rather by mechanisms that require the presence of complex microbiota.ConclusionsFurther studies of luminal carbohydrate levels and bacterial carbohydrate metabolism during intestinal inflammation will improve our understanding of the pathogenesis of IBDs and may lead to the development of novel therapies for these diseases.

Dataset Information

Regulation of Mannitol Metabolism in Enterococcus faecalis and Association with par_EF0409 Toxin-Antitoxin Locus Function.

Publications

Regulation of Mannitol Metabolism in Enterococcus faecalis and Association with <i>par</i><sub>EF0409</sub> Toxin-Antitoxin Locus Function.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets