A novel CsrA titration mechanism regulates fimbrial gene expression in Salmonella typhimurium.

ABSTRACT: A hierarchical control of fimbrial gene expression limits laboratory grown cultures of Salmonella enterica serovar typhimurium (S. typhimurium) to the production of type I fimbriae encoded by the fimAICDHF operon. Here we show that an unlikely culprit, namely the 5'-untranslated region (5'-UTR) of a messenger (m)RNA, coordinated the regulation. Binding of CsrA to the 5'-UTR of the pefACDEF transcript was required for expression of plasmid-encoded fimbriae. The 5'-UTR of the fimAICDHF transcript cooperated with two small untranslated RNAs, termed CsrB and CsrC, in antagonizing the activity of the RNA binding protein CsrA. Through this post-transcriptional mechanism, the 5'-UTR of the fimAICDHF transcript prevented production of PefA, the major structural subunit of plasmid-encoded fimbriae.

SUBMITTER: Sterzenbach T 

PROVIDER: S-EPMC3817462 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature