PMID:12068810

From EcoliWiki
Jump to navigation Jump to search
Citation

Binns, N and Masters, M (2002) Expression of the Escherichia coli pcnB gene is translationally limited using an inefficient start codon: a second chromosomal example of translation initiated at AUU. Mol. Microbiol. 44:1287-98

Abstract

Expression of the gene pcnB, encoding the dispensable Escherichia coli poly(A) polymerase (PAPI), which is toxic when overproduced, was investigated. Its promoter was identified and found to be moderately strong when used to express a beta-galactosidase reporter. Expression levels were not affected by increasing or decreasing PcnB concentration. Translation of pcnB was found to initiate from the non-canonical initiation codon AUU. The only other coli gene reported to use AUU as initiation codon is infC, which encodes the initiation factor IF-3. AUU, in common with other rarely used initiation codons, is discriminated against by IF-3, resulting in the aborting of most AUU-promoted initiation events. This enables AUU to form part of an autoregulatory circuit controlling IF-3 production. We show that InfC discrimination reduces PcnB production fivefold. This is the first instance of this mechanism being used to limit severely the production of a potentially toxic product.

Links

PubMed

Keywords

Base Sequence; Codon, Initiator/genetics; Escherichia coli/genetics; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Genes, Bacterial; Molecular Sequence Data; Mutagenesis, Site-Directed; Polynucleotide Adenylyltransferase/genetics; Polynucleotide Adenylyltransferase/metabolism; Promoter Regions, Genetic; Protein Biosynthesis; RNA, Messenger/genetics

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.