title: Hfq binding at RhlB-recognition region of RNase E is crucial for the rapid degradation of target mRNAs mediated by sRNAs in Escherichia coli.
abstract: An RNA chaperon Hfq along with Hfq-binding sRNAs stably binds to RNase E in Escherichia coli. The role of the Hfq-RNase E interaction is to recruit RNase E to target mRNAs of sRNAs resulting in the rapid degradation of the mRNA-sRNA hybrid. The C-terminal scaffold region of RNase E is responsible for the interaction with Hfq. Here, we demonstrate that the scaffold region can be deleted up to residue 750 without losing the ability to cause the rapid degradation of target mRNAs mediated by Hfq/sRNAs. The truncated RNase E750 can still bind to Hfq although the truncation significantly reduces the Hfq-binding ability. We conclude that the subregion between 711 and 750 is sufficient for the functional interaction with Hfq to support the rapid degradation of ptsG mRNA although additional subregions within the scaffold are also involved in Hfq binding. Deletion of the 702-750 region greatly impairs the ability of RNase E to cause the degradation of ptsG mRNA. In addition, a polypeptide corresponding to the scaffold region binds to Hfq without the help of RNA. Finally, we demonstrate that overexpression of RhlB partially inhibits the Hfq binding to RNase E and the rapid degradation of ptsG mRNA.
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Mieko
authors.initials: M
authors.lastname: Yagi
authors.forename: Teppei
authors.initials: T
authors.lastname: Morita
authors.forename: Hiroji
authors.initials: H
authors.lastname: Aiba
mesh_terms: D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D035001:Host Factor 1 Protein / Q000378:metabolism*; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020871:RNA Stability; D034741:RNA, Small Interfering / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D029968:Escherichia coli Proteins; C087373:Hfq protein, E coli; D035001:Host Factor 1 Protein; D034741:RNA, Small Interfering; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D004722:Endoribonucleases; C022537:ribonuclease E; C502431:RhlB protein, E coli; D053487:DEAD-box RNA Helicases