Division accuracy in a stochastic model of Min oscillations in Escherichia coli.
Accurate cell division in Escherichia coli requires the Min proteins MinC, MinD, and MinE as well as the presence of nucleoids. MinD and MinE exhibit spatial oscillations, moving from pole to pole of the bacterium, resulting in an average MinD concentration that is low at the center of the cell and high at the poles. This concentration minimum is thought to signal the site of cell division. Deterministic models of the Min oscillations reproduce many observed features of the system, including the concentration minimum of MinD. However, there are only a few thousand Min proteins in a bacterium, so stochastic effects are likely to play an important role. Here, we show that Monte Carlo simulations with a large number of proteins agree well with the results from a deterministic treatment of the equations. The location of minimum local MinD concentration is too variable to account for cell division accuracy in wild-type, but is consistent with the accuracy of cell division in cells without nucleoids. This finding confirms the need to include additional mechanisms, such as reciprocal interactions with the cell division ring or positioning of the nucleoids, to explain wild-type accuracy.
Kerr
Rex A
RA
Computational Neurobiology Laboratory and Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA. kerr@salk.edu
Levine
Herbert
H
Sejnowski
Terrence J
TJ
Rappel
Wouter-Jan
WJ
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D055592:Biophysical Phenomena; D001703:Biophysics; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002455:Cell Division; D004926:Escherichia coli / Q000166:cytology* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008954:Models, Biological; D009010:Monte Carlo Method; D013269:Stochastic Processes
D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; C093548:MinE protein, E coli; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli