Influence of translational efficiency on the stability of the mRNA for ribosomal protein S20 in Escherichia coli.

AUTOR(ES)

Rapaport, L R

RESUMO

A set of plasmids was constructed so as to contain point mutations which limit the efficiency and/or extent of translation of the gene for ribosomal protein S20. These plasmids were transformed into strains carrying mutations in the genes for polynucleotide phosphorylase (pnp-7), RNase E (rne-1), or both. Subsequently, the effect of translational efficiency on mRNA abundance and chemical half-life was determined. The data indicated that mutations altering translational efficiency also affected mRNA levels over a 10-fold range. This variation in mRNA abundance occurred independently of mutations in either RNase E or polynucleotide phosphorylase, both of which determine the stability of the S20 mRNAs. Moreover, a mutation at codon 15 which caused premature termination of translation of the S20 mRNA did not significantly reduce its stability in different genetic backgrounds. We propose a model in which initiation of translation competes for early steps in mRNA turnover, which could be the binding of RNase E itself or as a complex to one or more sites near the 5' terminus of the S20 mRNA.

Documentos Relacionados

• Posttranscriptional regulation of ribosomal protein S20 and stability of the S20 mRNA species.
• Stabilization of the 3' one-third of Escherichia coli ribosomal protein S20 mRNA in mutants lacking polynucleotide phosphorylase.
• Affinities of ribosomal protein S20 and C-terminal deletion mutants for 16S rRNA and S20 mRNA.
• Specific endonucleolytic cleavage of the mRNA for ribosomal protein S20 of Escherichia coli requires the product of the ams gene in vivo and in vitro.
• Role of mRNA translational efficiency in bovine growth hormone expression in Escherichia coli.