biostudies-literatureUnknown31(13)Chen JNational Cancer InstituteNational Institutes of HealthCenter for Cancer ResearchMismatch repair (MMR) is a conserved mechanism exploited by cells to correct DNA replication errors both in growing cells and under nongrowing conditions. Hfq (host factor for RNA bacteriophage Qβ replication), a bacterial Lsm family RNA-binding protein, chaperones RNA-RNA interactions between regulatory small RNAs (sRNAs) and target messenger RNAs (mRNAs), leading to alterations of mRNA translation and/or stability. Hfq has been reported to post-transcriptionally repress the DNA MMR gene <i>mutS</i> in stationary phase, possibly limiting MMR to allow increased mutagenesis. Here we report that Hfq deploys dual mechanisms to control <i>mutS</i> expression. First, Hfq binds directly to an (AAN)₃ motif within the <i>mutS</i> 5' untranslated region (UTR), repressing translation in tGenes & development1382-1395https://www.ebi.ac.uk/biostudies/studies/S-EPMC5580658biostudies-literatureHfq links translation repression to stress-induced mutagenesis in <i>E. coli</i>.PMC5580658Chen JGottesman SfalseHfq links translation repression to stress-induced mutagenesis in <i>E. coli</i>.Mismatch repair (MMR) is a conserved mechanism exploited by cells to correct DNA replication errors both in growing cells and under nongrowing conditions. Hfq (host factor for RNA bacteriophage Qβ replication), a bacterial Lsm family RNA-binding protein, chaperones RNA-RNA interactions between regulatory small RNAs (sRNAs) and target messenger RNAs (mRNAs), leading to alterations of mRNA translation and/or stability. Hfq has been reported to post-transcriptionally repress the DNA MMR gene <i>mutS</i> in stationary phase, possibly limiting MMR to allow increased mutagenesis. Here we report that Hfq deploys dual mechanisms to control <i>mutS</i> expression. First, Hfq binds directly to an (AAN)₃ motif within the <i>mutS</i> 5' untranslated region (UTR), repressing translation in t2017-01-01T00:00:00Z2017 Jul2025-04-22T03:43:10.403Z2019-03-27T02:55:11ZS-EPMC55806582879418610.1101/gad.302547.117