Pleiotropic effects of the rne∆MTS allele on RNA degradation

ABSTRACT: Localization of RNase E to the inner membrane in Escherichia coli is well documented, but the functional consequences of this localization are largely unknown. Here we characterize the rne∆MTS strain, which expresses cytoplasmic RNase E (cRNase E). CsrB and CsrC regulatory RNAs are stabilized in the rne∆MTS strain resulting in leaky glycogen expression. There is a small but significant global slowdown in mRNA degradation with no bias considering function or localization of encoded proteins. RNase E is a stable protein, but cRNase E is unstable with a half-life equal to the doubling time of exponentially growing cells. cRNase E instability is compensated by increased synthesis. Co-purification experiments show that cRNase E associates with RhlB, enolase and PNPase to form a cytoplasmic RNA degradosome. Measurements in multiple turnover assays show that there is no difference in Km or kcat between cRNase E and RNase E. In contrast to the global slowdown of mRNA degradation, the inactivation of a ribosome-free lacZ transcript is faster in the rne∆MTS strain. We discuss how the association of RNase E with the inner cytoplasmic membrane is important for carbon storage regulation, degradation of polyribosomal mRNA, protection of ribosome-free transcripts from inactivation and stability of RNase E.

ORGANISM(S): Escherichia coli K-12 Escherichia coli str. K-12 substr. MG1655

PROVIDER: GSE118058 | GEO | 2019/11/25

REPOSITORIES: GEO