Figure 4.

Knockout model for behavior of M. xanthus mutant cell lines. The model is optimized to accurately depict cell behavior consistent with known mutant phenotypes by setting activity for a given protein to zero. (a) Both FrzCD and FrzF knockout simulations cause loss of FrzS and AglZ activity indicating the entire pathway is disrupted, resulting in FrzS and AglZ remaining trapped at one cell pole and constitutive cell motility in one direction. (b) FrzG knockout simulation causes a hyper-reversing phenotype, in which cellular reversals increase to roughly once per 3.5 min. (c) Knockout of MglB causes hyper-activity of MglA, and therefore FrzS and AglZ, leading to rapid cell reversals, which matches the mglB hyper-reversing mutant phenotype of ∼ 2.5 min. (d) Knockout of MglA, however, results in rapid shutdown of any FrzS or AglZ activity and a nonmotile phenotype, which matches observed phenotypes. To see this figure in color, go online.