GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com


Jump to: navigation, search

Donovan, WP and Kushner, SR (1986) Polynucleotide phosphorylase and ribonuclease II are required for cell viability and mRNA turnover in Escherichia coli K-12. Proc. Natl. Acad. Sci. U.S.A. 83:120-4


The isolation of a temperature-sensitive allele of RNase II (rnb) by in vitro mutagenesis has permitted the demonstration that RNase II and polynucleotide phosphorylase (PNPase) are required for cell viability and mRNA turnover in Escherichia coli. Double-mutant strains carrying the pnp-7 and rnb-500 alleles (PNPase deficient and RNase II thermolabile) ceased growing in Luria broth within 30 min after shift to the nonpermissive temperature. Cessation of growth was accompanied by an accumulation of mRNA fragments 100-1500 nucleotides long. In contrast, single-mutant and wild-type control strains grew normally at the nonpermissive temperature and did not accumulate mRNA. No significant changes in rRNA patterns were observed in any of the strains.


PubMed PMC322803


Drug Stability; Escherichia coli/enzymology; Escherichia coli/genetics; Escherichia coli/growth & development; Exoribonucleases/genetics; Exoribonucleases/physiology; Genes, Bacterial; Half-Life; Hot Temperature; Kinetics; Mutation; Nucleic Acid Hybridization; Polyribonucleotide Nucleotidyltransferase/genetics; Polyribonucleotide Nucleotidyltransferase/physiology; RNA, Bacterial/metabolism; RNA, Messenger/metabolism



Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status


GO:0006402: mRNA catabolic process



As shown in Table 2, RNase II and PNPase were used in a pulse-chase to measure the half-life of the radioactive labeled mRNA. RNase II was a mutant strain that would grow at 44 degrees Celsius. First, the mRNA and the RNase II/PNPase were incubated at 30 degrees Celsius then shifted to 44 degrees Celsius. At 44 degrees Celsius PNPase cannot function, but RNase II is still able to function. The table shows that there was a decrease in the degradation of mRNA when the temperature was raised to 44 degrees Celsius which corresponds to a loss of PNPase function. These results demonstrate that PNPase is important to the catabolic process of mRNA.


See also


See Help:References for how to manage references in GONUTS.