We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Effects of Global and Specific DNA-Binding Proteins on Transcriptional Regulation of the E. coli bgl Operon.
- Authors
Tran, Dennis; Zhang, Zhongge; Lam, Katie Jing Kay; Saier Jr., Milton H.
- Abstract
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.
- Subjects
ESCHERICHIA coli; DNA-binding proteins; OPERONS; GENETIC transcription regulation; TRANSCRIPTION factors; REPORTER genes; BINDING sites
- Publication
International Journal of Molecular Sciences, 2022, Vol 23, Issue 18, pN.PAG
- ISSN
1661-6596
- Publication type
Article
- DOI
10.3390/ijms231810343