title: Influence of translational efficiency on the stability of the mRNA for ribosomal protein S20 in Escherichia coli.
abstract: 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.
authors.affiliation: Department of Biochemistry, University of Western Ontario, London, Canada.
authors.forename: L R
authors.initials: LR
authors.lastname: Rapaport
authors.forename: G A
authors.initials: GA
authors.lastname: Mackie
mesh_terms: D001483:Base Sequence; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006207:Half-Life; D006358:Hot Temperature; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D008969:Molecular Sequence Data; D017354:Point Mutation; D011117:Polyribonucleotide Nucleotidyltransferase / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D011489:Protein Denaturation; D012333:RNA, Messenger / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012269:Ribosomal Proteins / Q000096:biosynthesis / Q000235:genetics*; D013045:Species Specificity; D014170:Transformation, Genetic
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; C029611:ribosomal protein S20; D007544:Isopropyl Thiogalactoside; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; C022537:ribonuclease E