Degradation of mRNA in Escherichia coli

Abstract

SummaryDegradation of messenger RNAs (mRNAs) is a universal process that occurs in every cell and has important implications for nucleotide metabolism and gene expression. One organism in which mRNA degradation has been thoroughly studied is the bacterium Escherichia coli (E. coli). In this review I describe what is presently known about the different processes involved in the conversion of mRNAs from high molecular weight species to mononucleotides in E. coli. The ribonucleases and accessory factors involved in mRNA degradation, and features on mRNAs that make them resistant or sensitive to degradation will also be described. At the conclusion of this review, some of the anticipated directions of future research on this topic will be discussed.

Identification and Analysis of Escherichia coli Ribonuclease E Dominant-Negative Mutants

“…pNRNE5 encodes amino acids 1-498 of the RNase E N-terminal domain followed by a hexahistidine sequence (Lee et al 2002). Strains WM1/F9, CJ1830, and CJ1825 have been previously described ( Jain and Belasco 1996;Jain 2002). The mutator strain used for plasmid mutagenesis is a derivative of XL-1 Red (Stratagene, La Jolla, CA) that contains an F9lacI q element to prevent overexpression of RNase E when transformed with pLAC-RNE.…”

A Secondary Structure in the 5' Untranslated Region ofadhEmRNA Required for RNase G-Dependent Regulation

“…In bacteria, RNA is degraded by several types of RNase that target different sites at different efficiencies. 1) In Escherichia coli, the degradation of mRNAs begins with several internal cleavages by endoribonucleases such as RNase E, RNase G, RNase III, and RNase P. [2][3][4] The resulting fragments are then subjected to digestion in a 3 0 -to-5 0 direction by exonucleases such as RNase II, PNPase, and RNase R. 2,3) E. coli RNase G, encoded by the rng gene, was originally identified as an endoribonuclease that generates the mature 5 0 -end of 16S rRNA. 5,6) Recently, it was reported that ribosomes containing unprocessed 16S rRNA in rng mutant cells exhibited defects in proofreading in protein synthesis.…”

Expression, purification and evaluation of recombinant human Syntaxin 18 as an endoribonuclease.

“…mRNA has been recognized as the most unstable nucleic acid in the cell when compared to its counterparts, DNA, tRNA, and rRNA (Jain 2002). This instability, observed as the relative half-life of mRNA molecules, is intrinsic to the finding that control of mRNA half-lives can have great consequences on overall gene expression in the cell.…”

“…This instability, observed as the relative half-life of mRNA molecules, is intrinsic to the finding that control of mRNA half-lives can have great consequences on overall gene expression in the cell. Controlling gene expression at this level, by modifying mRNA half-lives, allows growing cells to quickly and efficiently adapt to changing environments (Jain 2002;Takayama et al 2000).…”

“…In E. coli, mRNA turnover processes are carried out by a set of over a dozen ribonucleases (Jain 2002), some with more important roles than others. By far the most common pathway involves endonucleolytic cleavage by RNase E, and will be discussed in the most detail here.…”