PMID:9484892
| Citation |
Plumbridge, J (1998) Control of the expression of the manXYZ operon in Escherichia coli: Mlc is a negative regulator of the mannose PTS. Mol. Microbiol. 27:369-80 |
|---|---|
| Abstract |
The manXYZ operon of Escherichia coli encodes a sugar transporter of the phosphoenol pyruvate (PEP)-dependent phosphotransferase system, which is capable of transporting many sugars, including glucose, mannose and the aminosugars, glucosamine and N-acetylglucosamine. Transcription of manX is strongly dependent on cyclic AMP (cAMP)/cAMP receptor protein (CAP). A cAMP/CAP binding site is located at -40.5, and activation by cAMP/CAP is shown to be typical of a class II promoter. The 5' end of a transcript, potentially encoding two proteins, is expressed divergently from the manXYZ operon. Previously, two binding sites for the NagC repressor were detected upstream of manX, but a mutation in nagC has very little effect on manX expression. However, a mutation in the mlc gene, encoding a homologue of nagC, results in a threefold derepression of manX expression, suggesting that this protein is a more important regulator of manX expression than NagC. The Mlc protein binds to the NagC operators, binding preferentially to the promoter-proximal operator. Plasmids overproducing either the NagC protein or the Mlc protein repress the expression of manX, but the effect of the Mlc protein is stronger. The mlc gene is shown to be allelic with the previously characterized dgsA mutation affecting the mannose phosphoenolpyruvate-dependent phosphotransferase system (PTS). |
| Links | |
| Keywords |
Bacterial Outer Membrane Proteins/genetics; Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Base Sequence; Binding Sites; Cyclic AMP; DNA, Bacterial; Escherichia coli/enzymology; Escherichia coli/genetics; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Molecular Sequence Data; Mutagenesis; Operon; Peptide Chain Initiation, Translational; Phosphoenolpyruvate Sugar Phosphotransferase System/genetics; Promoter Regions, Genetic; Repressor Proteins/genetics; Repressor Proteins/metabolism; Transcription Factors; Transcription, Genetic; Viral Proteins/genetics |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.