Nucleotide sequence and genetic characterization reveal six essential genes for the LIV-I and LS transport systems of Escherichia coli.

Adams, Mark D.; Wagner, Lois M.; Graddis, Thomas J.; Landick, Robert; Antonucci, Tammy K.; Gibson, Amy L.; Oxender, Dale L.

doi:10.1016/s0021-9258(19)38417-0

Cited by 107 publications

(18 citation statements)

References 50 publications

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“…3). Of the 42 bacterial species, only ten showed counts for the five necessary genes to encode the whole LIV-I/LS transport system and to functionally mediate transport into the bacterial cytoplasm (Adams et al 1990). Interestingly, 90% of the gene counts belonged only to two species; Faecalibacterium prausnitzii which accounted for 70-80% and Roseburia hominis that contributed to 8-10% of the counts.…”

Section: Contribution Of Gut Bacterial Metabolism To Serum Bcaamentioning

confidence: 99%

A higher bacterial inward BCAA transport driven by Faecalibacterium prausnitzii is associated with lower serum levels of BCAA in early adolescents

Morán-Ramos

Macías-Kauffer

López-Contreras

et al. 2021

Mol Med

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Background Elevations of circulating branched-chain amino acids (BCAA) are observed in humans with obesity and metabolic comorbidities, such as insulin resistance. Although it has been described that microbial metabolism contributes to the circulating pool of these amino acids, studies are still scarce, particularly in pediatric populations. Thus, we aimed to explore whether in early adolescents, gut microbiome was associated to circulating BCAA and in this way to insulin resistance. Methods Shotgun sequencing was performed in DNA from fecal samples of 23 early adolescents (10–12 years old) and amino acid targeted metabolomics analysis was performed by LC–MS/MS in serum samples. By using the HUMAnN2 algorithm we explored microbiome functional profiles to identify whether bacterial metabolism contributed to serum BCAA levels and insulin resistance markers. Results We identified that abundance of genes encoding bacterial BCAA inward transporters were negatively correlated with circulating BCAA and HOMA-IR (P < 0.01). Interestingly, Faecalibacterium prausnitzii contributed to approximately ~ 70% of bacterial BCAA transporters gene count. Moreover, Faecalibacterium prausnitzii abundance was also negatively correlated with circulating BCAA (P = 0.001) and with HOMA-IR (P = 0.018), after adjusting for age, sex and body adiposity. Finally, the association between Faecalibacterium genus and BCAA levels was replicated over an extended data set (N = 124). Conclusions We provide evidence that gut bacterial BCAA transport genes, mainly encoded by Faecalibacterium prausnitzii, are associated with lower circulating BCAA and lower insulin resistance. Based on the later, we propose that the relationship between Faecalibacterium prausnitzii and insulin resistance, could be through modulation of BCAA.

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Section: Contribution Of Gut Bacterial Metabolism To Serum Bcaamentioning

confidence: 99%

A higher bacterial inward BCAA transport driven by Faecalibacterium prausnitzii is associated with lower serum levels of BCAA in early adolescents

Morán-Ramos

Macías-Kauffer

López-Contreras

et al. 2021

Mol Med

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“…The remaining three cases show a smaller fraction (15-20%) of genes restored to the WT levels. Genes with restored expression in ∆dgk-sup strains include the liv branched-chain amino acid transport system [50] and the molybdate and maltose transporter genes. In ∆entC, the carAB glutamine catabolism genes, codB cytosine transport gene, and nadA NAD + biosynthetic gene are restored to WT levels by the sup2 and sup3 mutations.…”

Section: Transcriptomic Analysis Identifies Expression Changes Associ...mentioning

confidence: 99%

Experimental evolution of diverse Escherichia coli metabolic mutants identifies genetic loci for convergent adaptation of growth rate

Wytock¹,

Fiebig²,

Willett³

et al. 2018

PLoS Genet

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Cell growth is determined by substrate availability and the cell’s metabolic capacity to assimilate substrates into building blocks. Metabolic genes that determine growth rate may interact synergistically or antagonistically, and can accelerate or slow growth, depending on genetic background and environmental conditions. We evolved a diverse set of Escherichia coli single-gene deletion mutants with a spectrum of growth rates and identified mutations that generally increase growth rate. Despite the metabolic differences between parent strains, mutations that enhanced growth largely mapped to core transcription machinery, including the β and β’ subunits of RNA polymerase (RNAP) and the transcription elongation factor, NusA. The structural segments of RNAP that determine enhanced growth have been previously implicated in antibiotic resistance and in the control of transcription elongation and pausing. We further developed a computational framework to characterize how the transcriptional changes that occur upon acquisition of these mutations affect growth rate across strains. Our experimental and computational results provide evidence for cases in which RNAP mutations shift the competitive balance between active transcription and gene silencing. This study demonstrates that mutations in specific regions of RNAP are a convergent adaptive solution that can enhance the growth rate of cells from distinct metabolic states.

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“…Similarly, operon nadABC existed only in M. curtisii , enabling them biosynthesize NAD + in both the salvage and the de novo pathways. Another M. curtisii -specific region contained genes of LIV system, which is responsible for the transport of branched-chain amino acids, such as leucine, isoleucine, and valine ( Adams et al, 1990 ).…”

Section: Resultsmentioning

confidence: 99%

Genomic Insights Into the Interspecific Diversity and Evolution of Mobiluncus, a Pathogen Associated With Bacterial Vaginosis

Wang

Liu

2022

Front. Microbiol.

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Bacterial vaginosis (BV) is a common vaginal infection and has been associated with increased risk for a wide array of health issues. BV is linked with a variety of heterogeneous pathogenic anaerobic bacteria, among which Mobiluncus is strongly associated with BV diagnosis. However, their genetic features, pathogenicity, interspecific diversity, and evolutionary characters have not been illustrated at genomic level. The current study performed phylogenomic and comparative genomic analyses of Mobiluncus. Phylogenomic analyses revealed remarkable phylogenetic distinctions among different species. Compared with M. curtisii, M. mulieris had a larger genome and pangenome size with more insertion sequences but less CRISPR-Cas systems. In addition, these two species were diverse in profile of virulence factors, but harbored similar antibiotic resistance genes. Statistically different functional genome profiles between strains from the two species were determined, as well as correlations of some functional genes/pathways with putative pathogenicity. We also showed that high levels of horizontal gene transfer might be an important strategy for species diversification and pathogenicity. Collectively, this study provides the first genome sequence level description of Mobiluncus, and may shed light on its virulence/pathogenicity, functional diversification, and evolutionary dynamics. Our study could facilitate the further investigations of this important pathogen, and might improve the future treatment of BV.

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Nucleotide sequence and genetic characterization reveal six essential genes for the LIV-I and LS transport systems of Escherichia coli.

Cited by 107 publications

References 50 publications

A higher bacterial inward BCAA transport driven by Faecalibacterium prausnitzii is associated with lower serum levels of BCAA in early adolescents

A higher bacterial inward BCAA transport driven by Faecalibacterium prausnitzii is associated with lower serum levels of BCAA in early adolescents

Experimental evolution of diverse Escherichia coli metabolic mutants identifies genetic loci for convergent adaptation of growth rate

Genomic Insights Into the Interspecific Diversity and Evolution of Mobiluncus, a Pathogen Associated With Bacterial Vaginosis

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