Worrall, Jonathan AR and Howe, Françoise S and McKay, Adam R and Robinson, Carol V and Luisi, Ben F (2008) Allosteric Activation of the ATPase Activity of the Escherichia coli RhlB RNA Helicase. Journal of Biological Chemistry, 283 (9). pp. 5567-5576. DOI https://doi.org/10.1074/jbc.m708620200
Worrall, Jonathan AR and Howe, Françoise S and McKay, Adam R and Robinson, Carol V and Luisi, Ben F (2008) Allosteric Activation of the ATPase Activity of the Escherichia coli RhlB RNA Helicase. Journal of Biological Chemistry, 283 (9). pp. 5567-5576. DOI https://doi.org/10.1074/jbc.m708620200
Worrall, Jonathan AR and Howe, Françoise S and McKay, Adam R and Robinson, Carol V and Luisi, Ben F (2008) Allosteric Activation of the ATPase Activity of the Escherichia coli RhlB RNA Helicase. Journal of Biological Chemistry, 283 (9). pp. 5567-5576. DOI https://doi.org/10.1074/jbc.m708620200
Abstract
Helicase B (RhlB) is one of the five DEAD box RNA-dependent ATPases found in Escherichia coli. Unique among these enzymes, RhlB requires an interaction with the partner protein RNase E for appreciable ATPase and RNA unwinding activities. To explore the basis for this activating effect, we have generated a di-cistronic vector that overexpresses a complex comprising RhlB and its recognition site within RNase E, corresponding to residues 696-762. Complex formation has been characterized by isothermal titration calorimetry, revealing an avid, enthalpy-favored interaction between the helicase and RNase E-(696-762) with an equilibrium binding constant (Ka) of at least 1 × 108 M-1. We studied ATPase activity of mutants with substitutions within the ATP binding pocket of RhlB and on the putative interaction surface that mediates recognition of RNase E. For comparisons, corresponding mutations were prepared in two other E. coli DEAD box ATPases, RhlE and SrmB. Strikingly, substitutions at a phenylalanine near the Q-motif found in DEAD box proteins boosts the ATPase activity of RhlB in the absence of RNA, but completely inhibits it in its presence. The data support the proposal that the protein-protein and RNA-binding surfaces both communicate allosterically with the ATPase catalytic center. We conjecture that this communication may govern the mechanical power and efficiency of the helicases, and is tuned in individual helicases in accordance with cellular function. © 2008 by The American Society for Biochemistry and Molecular Biology, Inc.
Item Type: | Article |
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Uncontrolled Keywords: | Escherichia coli; Multiprotein Complexes; Endoribonucleases; Escherichia coli Proteins; RNA, Bacterial; Amino Acid Substitution; Allosteric Regulation; Binding Sites; Amino Acid Motifs; Protein Structure, Quaternary; Protein Binding; Mutation, Missense; Adenosine Triphosphatases; DEAD-box RNA Helicases |
Subjects: | Q Science > QH Natural history > QH301 Biology |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 11 Oct 2011 11:19 |
Last Modified: | 07 Aug 2024 20:07 |
URI: | http://repository.essex.ac.uk/id/eprint/1077 |