title: RNaseE and RNA helicase B play central roles in the cytoskeletal organization of the RNA degradosome.
abstract: The RNA degradosome of Escherichia coli is a multiprotein complex that plays an essential role in normal RNA processing and decay. It was recently shown that the major degradosome constituents are organized in a coiled cytoskeletal-like structure that extends along the length of the cell. Here we show that the endoribonuclease E (RNaseE) and RNA helicase B (RhlB) components of the degradosome can each independently form coiled structures in the absence of the other degradosome proteins. In contrast, the cytoskeletal organization of the other degradosome proteins required the presence of the RNaseE or RhlB coiled elements. Although the RNaseE and RhlB structures were equally competent to support the helical organization of polynucleotide phosphorylase, the cytoskeletal-like organization of enolase occurred only in the presence of the RNaseE coiled structure. The results indicate that the RNA degradosome proteins are components of the bacterial cytoskeleton rather than existing as randomly distributed multiprotein complexes within the cell and suggest a model for the cellular organization of the components within the helical degradosomal structure.
authors.affiliation: Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut 06032, USA. taghbalout@neuron.uchc.edu
authors.forename: Aziz
authors.initials: A
authors.lastname: Taghbalout
authors.forename: Lawrence
authors.initials: L
authors.lastname: Rothfield
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D008164:Luminescent Proteins / Q000378:metabolism; D008954:Models, Biological; D008968:Molecular Conformation; D009097:Multienzyme Complexes / Q000378:metabolism*; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D020365:RNA Helicases / Q000378:metabolism*; D012329:RNA, Bacterial
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; D009097:Multienzyme Complexes; D012329:RNA, Bacterial; C111244:degradosome; C054562:yellow fluorescent protein, Bacteria; D012313:RNA; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; C022537:ribonuclease E; C502431:RhlB protein, E coli; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases