Hfq-bridged ternary complex is important for translation activation of rpoS by DsrA

Weiwei Wang, Lijun Wang, Jihui Wu, Qingguo Gong, Yunyu Shi

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

The rpoS mRNA, which encodes the master regulator σS of general stress response, requires Hfq-facilitated base pairing with DsrA small RNA for efficient translation at low temperatures. It has recently been proposed that one mechanism underlying Hfq action is to bridge a transient ternary complex by simultaneously binding to rpoS and DsrA. However, no structural evidence of Hfq simultaneously bound to different RNAs has been reported. We detected simultaneous binding of Hfq to rpoS and DsrA fragments. Crystal structures of AU6A Hfq A7 and Hfq A7 complexes were resolved using 1.8-and 1.9-Å resolution, respectively. Ternary complex has been further verified in solution by NMR. In vivo, activation of rpoS translation requires intact Hfq, which is capable of bridging rpoS and DsrA simultaneously into ternary complex. This ternary complex possibly corresponds to a meta-stable transition state in Hfq-facilitated small RNA-mRNA annealing process.

Original languageEnglish (US)
Pages (from-to)5938-5948
Number of pages11
JournalNucleic acids research
Volume41
Issue number11
DOIs
StatePublished - Jun 1 2013

    Fingerprint

ASJC Scopus subject areas

  • Genetics

Cite this