title: Studies of the RNA degradosome-organizing domain of the Escherichia coli ribonuclease RNase E.
abstract: The hydrolytic endoribonuclease RNase E, which is widely distributed in bacteria and plants, plays key roles in mRNA degradation and RNA processing in Escherichia coli. The enzymatic activity of RNase E is contained within the conserved amino-terminal half of the 118 kDa protein, and the carboxy-terminal half organizes the RNA degradosome, a multi-enzyme complex that degrades mRNA co-operatively and processes ribosomal and other RNA. The study described herein demonstrates that the carboxy-terminal domain of RNase E has little structure under native conditions and is unlikely to be extensively folded within the degradosome. However, three isolated segments of 10-40 residues, and a larger fourth segment of 80 residues, are predicted to be regions of increased structural propensity. The larger of these segments appears to be a protein-RNA interaction site while the other segments possibly correspond to sites of self-recognition and interaction with the other degradosome proteins. The carboxy-terminal domain of RNase E may thus act as a flexible tether of the degradosome components. The implications of these and other observations for the organization of the RNA degradosome are discussed.
authors.affiliation: Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
authors.forename: Anastasia J
authors.initials: AJ
authors.lastname: Callaghan
authors.forename: Jukka P
authors.initials: JP
authors.lastname: Aurikko
authors.forename: Leopold L
authors.initials: LL
authors.lastname: Ilag
authors.forename: J
authors.initials: J
authors.lastname: Günter Grossmann
authors.forename: Vidya
authors.initials: V
authors.lastname: Chandran
authors.forename: Karin
authors.initials: K
authors.lastname: Kühnel
authors.forename: Leonora
authors.initials: L
authors.lastname: Poljak
authors.forename: Agamennon J
authors.initials: AJ
authors.lastname: Carpousis
authors.forename: Carol V
authors.initials: CV
authors.lastname: Robinson
authors.forename: Martyn F
authors.initials: MF
authors.lastname: Symmons
authors.forename: Ben F
authors.initials: BF
authors.lastname: Luisi
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D004722:Endoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism*; D010751:Phosphopyruvate Hydratase / Q000302:isolation & purification / Q000378:metabolism; D011117:Polyribonucleotide Nucleotidyltransferase / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000737:chemistry* / Q000378:metabolism*; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D009097:Multienzyme Complexes; D012329:RNA, Bacterial; D016601:RNA-Binding Proteins; C111244:degradosome; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; C022537:ribonuclease E; D020365:RNA Helicases; D010751:Phosphopyruvate Hydratase