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Turnover of mRNAs is one of the essential functions of RNase E
Author(s) -
Hammarlöf Disa L.,
Bergman Jessica M.,
Garmendia Eva,
Hughes Diarmaid
Publication year - 2015
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13100
Subject(s) - biology , endoribonuclease , rnase p , messenger rna , ribosomal rna , rnase mrp , microbiology and biotechnology , transcription (linguistics) , transfer rna , ribosomal protein , gene , rna , genetics , ribosome , linguistics , philosophy
Summary RNase E is an essential bacterial endoribonuclease with a central role in processing tRNAs and rRNA , and turning over mRNAs . Previous studies in strains carrying mutations in the rne structural gene have shown that tRNA processing is likely to be an essential function of RNase E but have not determined whether mRNA turnover is also an essential function. To address this we selected extragenic suppressors of temperature‐sensitive mutations in rne that cause a large increase in mRNA half‐life at the non‐permissive temperature. Fifteen suppressors were mapped to three different loci: relBE (toxin‐antitoxin system); vacB ( RNase R ); and rpsA (ribosomal protein S1). Each suppressor class has the potential to interact with mRNA and each restores wild‐type levels of m R NA turnover but does not reverse the minor defects in tRNA and rRNA processing. RelE toxin is especially interesting because its only known activity is to cleave mRNAs in the ribosomal A‐site. The relBE suppressor mutations increase transcription of relE , and controlled overexpression of RelE alone was sufficient to suppress the rne ts phenotype. Suppression increased turnover of some major mRNAs ( tufA , ompA ) but not all mRNAs . We propose that turnover of some mRNAs is one of the essential functions of RNase E .