The Escherichia coli RNA degradosome: structure, function and relationship in other ribonucleolytic multienzyme complexes.
mRNA instability is an intrinsic property that permits timely changes in gene expression by limiting the lifetime of a transcript. The RNase e of Escherichia coli is a single-strand-specific endo-nuclease involved in the processing of rRNA and the degradation of mRNA. A nucleolytic multi-enzyme complex now known as the RNA degradosome was discovered during the purification and characterization of RNase E. Two other components are a 3' exoribonuclease (polynucleotide phosphorylase, PNPase) and a DEAD-box RNA helicase (RNA helicase B, RhlB). RNase E is a large multidomain protein with N-terminal ribonucleolytic activity, an RNA-binding domain and a C-terminal "scaffold" that binds PNPase, enolase and RhlB. RhlB by itself has little activity but is strongly stimiulated by its interaction with RNase E. RhlB in vitro can facilitate the degradation of structured RNA by PNPase. Since the discovery of the RNA degradosome in E. coli, related complexes have been described in other organisms.
Carpousis
A J
AJ
Laboratoire de Microbiologie et Génétique Moléculaire, Centre National de la Recherche Scientifique, UMR 5100, 118 Route de Narbonne, 31061 Toulouse Cedex, France. carpousi@ibcg.biotoul.fr
D004722:Endoribonucleases / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005057:Eukaryotic Cells; D005095:Exoribonucleases / Q000737:chemistry / Q000378:metabolism; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism*; D011117:Polyribonucleotide Nucleotidyltransferase / Q000737:chemistry / Q000378:metabolism*; D020365:RNA Helicases / Q000737:chemistry / Q000378:metabolism*; D020871:RNA Stability; D012329:RNA, Bacterial / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*
D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D012329:RNA, Bacterial; D012333:RNA, Messenger; C111244:degradosome; C056502:ribonuclease PH; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; D005095:Exoribonucleases; C081905:rng protein, E coli; C022537:ribonuclease E; D020365:RNA Helicases