Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-8-6
pubmed:abstractText
The bacterium Escherichia coli (E. coli) moves in its natural environment in a series of straight runs, interrupted by tumbles which cause change of direction. It performs chemotaxis towards chemo-attractants by extending the duration of runs in the direction of the source. When there is a spatial gradient in the attractant concentration, this bias produces a drift velocity directed towards its source, whereas in a uniform concentration, E. coli adapts, almost perfectly in case of methyl aspartate. Recently, microfluidic experiments have measured the drift velocity of E. coli in precisely controlled attractant gradients, but no general theoretical expression for the same exists. With this motivation, we study an analytically soluble model here, based on the Barkai-Leibler model, originally introduced to explain the perfect adaptation. Rigorous mathematical expressions are obtained for the chemotactic response function and the drift velocity in the limit of weak gradients and under the assumption of completely random tumbles. The theoretical predictions compare favorably with experimental results, especially at high concentrations. We further show that the signal transduction network weakens the dependence of the drift on concentration, thus enhancing the range of sensitivity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/CheB protein, Bacteria, http://linkedlifedata.com/resource/pubmed/chemical/CheR protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/Chemotactic Factors, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Methyltransferases, http://linkedlifedata.com/resource/pubmed/chemical/N-Methylaspartate, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cell Surface, http://linkedlifedata.com/resource/pubmed/chemical/Tar protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/methyl-accepting chemotaxis proteins
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1095-8541
pubmed:author
pubmed:copyrightInfo
Copyright 2010 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
7
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
99-106
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Theoretical results for chemotactic response and drift of E. coli in a weak attractant gradient.
pubmed:affiliation
Department of Physics and Astrophysics, Delhi University, St. Stephen's College, Delhi 110007, India.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't