Flagellar motor model.

<p>(A) Curves for as a function of the concentration of free CheY-P (no ligand depletion: solid blue line) and curves for as a function of total CheY-P (with ligand depletion: dashed blue line), with and expressed in terms of CW bias, the measured parameter of the flagellar motor corresponding to the fraction of time undergoing clockwise rotation. The dynamic range, defined as the ligand concentration range between values of or of 0.1 and 0.9, is represented by the shaded rectangles for the curves with and without ligand depletion. The open diamond points correspond to the measurements reported by Cluzel et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008449#pone.0008449-Cluzel1" target="_blank">[30]</a>. (B) Variations in the dynamic range due to ligand depletion as a function of the concentration of FliM for values of (the number of sites) = 10, 18, 34, and 100. For each value of , the curve for is computed based on an value set by (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008449#s4" target="_blank">Materials and Methods</a>, Eqn 11), where is fixed by the value used for , i.e. . (C) The ratio of the dynamic range for µM to the dynamic range for as a function of , the number of sites and calculated as in (B). Parameter values used for the curves in (A): , M, M, and , with a concentration of M. Calculation of ligand depletion effects as described in Eqn 9 of the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008449#s4" target="_blank">Material and Methods</a> section.