Regulation of gene expression: Cryptic &amp;#946;-glucoside (bgl) operon of Escherichia coli as a paradigm

Harwani, Dharmesh

doi:10.1590/s1517-83822014000400003

Cited by 11 publications

(8 citation statements)

References 42 publications

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“…E602 to utilize substrates from environmental resources for lactose metabolism, thereby gaining an adaptive advantage over competitors. Similar functions have been found in E. coli ( Harwani, 2014 ). Nevertheless, our analysis showed that the lac operon in Erwinia sp.…”

Section: Discussionsupporting

confidence: 84%

Hybrid de novo Genome Assembly of Erwinia sp. E602 and Bioinformatic Analysis Characterized a New Plasmid-Borne lac Operon Under Positive Selection

Xia

Wei

et al. 2021

Front. Microbiol.

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Our previous study identified a new β-galactosidase in Erwinia sp. E602. To further understand the lactose metabolism in this strain, de novo genome assembly was conducted by using a strategy combining Illumina and PacBio sequencing technology. The whole genome of Erwinia sp. E602 includes a 4.8 Mb chromosome and a 326 kb large plasmid. A total of 4,739 genes, including 4,543 protein-coding genes, 25 rRNAs, 82 tRNAs and 7 other ncRNAs genes were annotated. The plasmid was the largest one characterized in genus Erwinia by far, and it contained a number of genes and pathways responsible for lactose metabolism and regulation. Moreover, a new plasmid-borne lac operon that lacked a typical β-galactoside transacetylase (lacA) gene was identified in the strain. Phylogenetic analysis showed that the genes lacY and lacZ in the operon were under positive selection, indicating the adaptation of lactose metabolism to the environment in Erwinia sp. E602. Our current study demonstrated that the hybrid de novo genome assembly using Illumina and PacBio sequencing technologies, as well as the metabolic pathway analysis, provided a useful strategy for better understanding of the evolution of undiscovered microbial species or strains.

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Section: Discussionsupporting

confidence: 84%

Hybrid de novo Genome Assembly of Erwinia sp. E602 and Bioinformatic Analysis Characterized a New Plasmid-Borne lac Operon Under Positive Selection

Xia

Wei

et al. 2021

Front. Microbiol.

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“…3C). In most wild-type strains of E. coli, the bgl operon is cryptic but can be activated by a variety of cis-and trans-acting mutations (37,38). Once activated, full bgl expression requires a ␤-glucoside inducer and also cyclic AMP (cAMP) and the cAMP receptor protein (CRP) (39).…”

Section: Class Ii: Rna-binding-protein-mediated Transcription Attenuamentioning

confidence: 99%

Regulation of Bacterial Gene Expression by Transcription Attenuation

Turnbough

2019

Microbiol Mol Biol Rev

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SUMMARY A wide variety of mechanisms that control gene expression in bacteria are based on conditional transcription termination. Generally, in these mechanisms, a transcription terminator is located between a promoter and a downstream gene(s), and the efficiency of the terminator is controlled by a regulatory effector that can be a metabolite, protein, or RNA. The most common type of regulation involving conditional termination is transcription attenuation, in which the primary regulatory target is an essential element of a single terminator. The terminator can be either intrinsic or Rho dependent, with each presenting unique regulatory targets. Transcription attenuation mechanisms can be divided into five classes based primarily on the manner in which transcription termination is rendered conditional. This review summarizes each class of control mechanisms from a historical perspective, describes important examples in a physiological context and the current state of knowledge, highlights major advances, and discusses expectations of future discoveries.

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“…RpoS-dependent repression requires the presence of Crl [ 58 ], an RNA polymerase holoenzyme assembly factor [ 59 ]. In an rpoS mutant background, increased levels of BglG conferred a growth advantage to Bgl + cells during the stationary phase [ 60 , 61 ].…”

Section: Introductionmentioning

confidence: 99%

Effects of Global and Specific DNA-Binding Proteins on Transcriptional Regulation of the E. coli bgl Operon

Tran

Zhang

Lam

et al. 2022

IJMS

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Using reporter gene (lacZ) transcriptional fusions, we examined the transcriptional dependencies of the bgl promoter (Pbgl) and the entire operon regulatory region (Pbgl-bglG) on eight transcription factors as well as the inducer, salicin, and an IS5 insertion upstream of Pbgl. Crp-cAMP is the primary activator of both Pbgl and the bgl operon, while H-NS is a strong dominant operon repressor but only a weak repressor of Pbgl. H-NS may exert its repressive effect by looping the DNA at two binding sites. StpA is a relatively weak repressor in the absence of H-NS, while Fis also has a weak repressive effect. Salicin has no effect on Pbgl activity but causes a 30-fold induction of bgl operon expression. Induction depends on the activity of the BglF transporter/kinase. IS5 insertion has only a moderate effect on Pbgl but causes a much greater activation of the bgl operon expression by preventing the full repressive effects of H-NS and StpA. While several other transcription factors (BglJ, RcsB, and LeuO) have been reported to influence bgl operon transcription when overexpressed, they had little or no effect when present at wild type levels. These results indicate the important transcriptional regulatory mechanisms operative on the bgl operon in E. coli.

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Regulation of gene expression: Cryptic β-glucoside (bgl) operon of Escherichia coli as a paradigm

Cited by 11 publications

References 42 publications

Hybrid de novo Genome Assembly of Erwinia sp. E602 and Bioinformatic Analysis Characterized a New Plasmid-Borne lac Operon Under Positive Selection

Hybrid de novo Genome Assembly of Erwinia sp. E602 and Bioinformatic Analysis Characterized a New Plasmid-Borne lac Operon Under Positive Selection

Regulation of Bacterial Gene Expression by Transcription Attenuation

Effects of Global and Specific DNA-Binding Proteins on Transcriptional Regulation of the E. coli bgl Operon

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