Hfq: a bacterial Sm-like protein that mediates RNA-RNA interaction

Mol Cell. 2002 Jan;9(1):23-30. doi: 10.1016/s1097-2765(01)00436-1.


The bacterial Hfq protein modulates the stability or the translation of mRNAs and has recently been shown to interact with small regulatory RNAs in E. coli. Here we show that Hfq belongs to the large family of Sm and Sm-like proteins: it contains a conserved sequence motif, known as the Sm1 motif, forms a doughnut-shaped structure, and has RNA binding specificity very similar to the Sm proteins. Moreover, we provide evidence that Hfq strongly cooperates in intermolecular base pairing between the antisense regulator Spot 42 RNA and its target RNA. We speculate that Sm proteins in general cooperate in bimolecular RNA-RNA interaction and that protein-mediated complex formation permits small RNAs to interact with a broad range of target RNAs.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Autoantigens / genetics*
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Conserved Sequence
  • Escherichia coli
  • Escherichia coli Proteins*
  • Host Factor 1 Protein
  • Humans
  • Integration Host Factors
  • Molecular Sequence Data
  • Protein Binding
  • Protein Biosynthesis*
  • RNA, Bacterial / genetics
  • RNA, Bacterial / metabolism
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • Ribonucleoproteins, Small Nuclear*
  • snRNP Core Proteins


  • Autoantigens
  • Carrier Proteins
  • Escherichia coli Proteins
  • Host Factor 1 Protein
  • Integration Host Factors
  • RNA, Bacterial
  • RNA, Messenger
  • Ribonucleoproteins, Small Nuclear
  • integration host factor, E coli
  • snRNP Core Proteins