Expression of the Escherichia coli pcnB gene is translationally limited using an inefficient start codon: a second chromosomal example of translation initiated at AUU.

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