Conformational Spread in the Flagellar Motor Switch: A Model Study


Autoria(s): Rao, Christopher V.; Ma, Qi; Nicolau, Dan V.; Maini, Philip K.; Berry, Richard M.; Bai, Fan
Data(s)

2012

Resumo

The reliable response to weak biological signals requires that they be amplified with fidelity. In E. coli, the flagellar motors that control swimming can switch direction in response to very small changes in the concentration of the signaling protein CheY-P, but how this works is not well understood. A recently proposed allosteric model based on cooperative conformational spread in a ring of identical protomers seems promising as it is able to qualitatively reproduce switching, locked state behavior and Hill coefficient values measured for the rotary motor. In this paper we undertook a comprehensive simulation study to analyze the behavior of this model in detail and made predictions on three experimentally observable quantities: switch time distribution, locked state interval distribution, Hill coefficient of the switch response. We parameterized the model using experimental measurements, finding excellent agreement with published data on motor behavior. Analysis of the simulated switching dynamics revealed a mechanism for chemotactic ultrasensitivity, in which cooperativity is indispensable for realizing both coherent switching and effective amplification. These results showed how cells can combine elements of analog and digital control to produce switches that are simultaneously sensitive and reliable. © 2012 Ma et al.

Identificador

http://eprints.qut.edu.au/80288/

Publicador

PLOS

Relação

DOI:10.1371/journal.pcbi.1002523

Rao, Christopher V., Ma, Qi, Nicolau, Dan V., Maini, Philip K., Berry, Richard M., & Bai, Fan (2012) Conformational Spread in the Flagellar Motor Switch: A Model Study. PLoS Computational Biology, 8(5), e1002523-e1002523.

Direitos

The authors

Fonte

School of Mathematical Sciences; Science & Engineering Faculty

Tipo

Journal Article