Hfq: a bacterial Sm-like protein that mediates RNA-RNA interaction.
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.
Møller
Thorleif
T
Department of Biochemistry and Molecular Biology, University of Southern Denmark-Odense, Campusvej 55, DK-5230 M, Odense, Denmark.
Franch
Thomas
T
Højrup
Peter
P
Keene
Douglas R
DR
Bächinger
Hans Peter
HP
Brennan
Richard G
RG
Valentin-Hansen
Poul
P
D000595:Amino Acid Sequence; D001324:Autoantigens / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D035001:Host Factor 1 Protein; D006801:Humans; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D011485:Protein Binding; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D001324:Autoantigens; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D035001:Host Factor 1 Protein; D034982:Integration Host Factors; D012329:RNA, Bacterial; D012333:RNA, Messenger; D017411:Ribonucleoproteins, Small Nuclear; C440502:integration host factor, E coli; D055517:snRNP Core Proteins