Source and sink saturation does not significantly reduce the R ∼ P gradient except in very stringent saturation conditions.A) Schematic of localization of source and sink. B) Mathematical modeling of the R ∼ P concentration near the phosphatase pole [R ∼ P]phosnormalized to the total response regulator concentration [Rtot] for varying σp, and σk = 10 and 100/s. C) The effective phosphatase rate σp,eis high enough to outcompete diffusion except when the number of enzymes is less than 10% than of the substrate.
Tropini et al. BMC Biophysics 2012 5:17 doi:10.1186/2046-1682-5-17