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Computer simulation of the phosphorylation cascade controlling bacterial chemotaxis

Bray, Dennis and Bourret, Robert B. and Simon, Melvin I. (1993) Computer simulation of the phosphorylation cascade controlling bacterial chemotaxis. Molecular Biology of the Cell, 4 (5). pp. 469-482. ISSN 1059-1524.

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We have developed a computer program that simulates the intracellular reactions mediating the rapid (nonadaptive) chemotactic response of Escherichia coli bacteria to the attractant aspartate and the repellent Ni2+ ions. The model is built from modular units representing the molecular components involved, which are each assigned a known value of intracellular concentration and enzymatic rate constant wherever possible. The components are linked into a network of coupled biochemical reactions based on a compilation of widely accepted mechanisms but incorporating several novel features. The computer motor shows the same pattern of runs, tumbles and pauses seen in actual bacteria and responds in the same way as living bacteria to sudden changes in concentration of aspartate or Ni2+. The simulated network accurately reproduces the phenotype of more than 30 mutants in which components of the chemotactic pathway are deleted and/or expressed in excess amounts and shows a rapidity of response to a step change in aspartate concentration similar to living bacteria. Discrepancies between the simulation and real bacteria in the phenotype of certain mutants and in the gain of the chemotactic response to aspartate suggest the existence of additional as yet unidentified interactions in the in vivo signal processing pathway.

Item Type:Article
Additional Information:Copyright © 1993 by The American Society for Cell Biology Submitted January 22, 1993; Accepted March 5, 1993. Thanks to H. Berg, J. Pine, and J. Bower for encouragement, A. Brown for help with programming, J. Gegner and F. Dahlquist for providing results in advance of publication, and L. Alex and R. Swanson for useful discussions and comments on the manuscript. This work was supported by a grant from the UK Medical Research Council to D.B. and National Institutes of Health Grant AI-19296 to M.I.S.
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Deposited On:26 Dec 2006
Last Modified:26 Dec 2012 09:25

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