Studies of the RNA degradosome-organizing domain of the Escherichia coli ribonuclease RNase E.
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.
Callaghan
Anastasia J
AJ
Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
Aurikko
Jukka P
JP
Ilag
Leopold L
LL
Günter Grossmann
J
J
Chandran
Vidya
V
Kühnel
Karin
K
Poljak
Leonora
L
Carpousis
Agamennon J
AJ
Robinson
Carol V
CV
Symmons
Martyn F
MF
Luisi
Ben F
BF
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
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