title: Hfq: a bacterial Sm-like protein that mediates RNA-RNA interaction.
abstract: 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.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark-Odense, Campusvej 55, DK-5230 M, Odense, Denmark.
authors.forename: Thorleif
authors.initials: T
authors.lastname: Møller
authors.forename: Thomas
authors.initials: T
authors.lastname: Franch
authors.forename: Peter
authors.initials: P
authors.lastname: Højrup
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Keene
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Bächinger
authors.forename: Richard G
authors.initials: RG
authors.lastname: Brennan
authors.forename: Poul
authors.initials: P
authors.lastname: Valentin-Hansen
mesh_terms: 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
chemical_list: 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