PMID:17056747
| Citation |
Abdel-Hamid, AM and Cronan, JE (2007) Coordinate expression of the acetyl coenzyme A carboxylase genes, accB and accC, is necessary for normal regulation of biotin synthesis in Escherichia coli. J. Bacteriol. 189:369-76 |
|---|---|
| Abstract |
Transcription of the biotin (bio) biosynthetic operon of Escherichia coli is negatively regulated by the BirA protein, an atypical repressor protein in that it is also an enzyme. The BirA-catalyzed reaction involves the covalent attachment of biotin to AccB, a subunit of acetyl coenzyme (acetyl-CoA) carboxylase. The two functions of BirA allow regulation of the bio operon to respond to the intracellular concentrations of both biotin and unbiotinylated AccB. We report here that bio operon expression is down-regulated by overproduction of AccC, another acetyl-CoA carboxylase subunit known to form a complex with AccB. This down-regulation is eliminated when AccB and AccC are coordinately overexpressed, but only when the AccB partner is competent to bind AccC. Under AccC overexpression conditions AccB is underbiotinylated. These findings can be explained by a model in which excess AccC sequesters AccB in a complex that is a poor substrate for biotinylation. The observed disruption of biotin synthesis and attachment provides an excellent rationale for the observation that in the vast majority of sequenced bacterial genomes AccB and AccC are encoded in a two-gene operon. |
| Links |
PubMed PMC1797400 Online version:10.1128/JB.01373-06 |
| Keywords |
Acetyl-CoA Carboxylase/genetics; Acetyl-CoA Carboxylase/metabolism; Biotin/biosynthesis; Escherichia coli/enzymology; Escherichia coli/genetics; Escherichia coli/metabolism; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Gene Expression Regulation, Bacterial; Isoenzymes/genetics; Isoenzymes/metabolism; Models, Biological; Molecular Structure; Operon/genetics; Promoter Regions, Genetic; Transcription, Genetic |
| 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
<protect><annotationlinks/></protect>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
See also
References
See Help:References for how to manage references in EcoliWiki.
