FIGURE 5.

Activities and structural properties of DegS^ΔPDZ mutants and variants. A, steady-state rate of cleavage of a sub-K_m concentration of ³⁵S-labeled RseA by wild-type DegS^ΔPDZ and single and double mutant variants. For variants with detectable activity, values are averages (n = 3) ± 1 S.D. For variants with undetectable activity, error bars were set to a value of 5 m⁻¹ s⁻¹, which represents the approximate sensitivity of the assay. Assay conditions were the same as in Fig. 2A. B, subunits from the inactive R178A, Q191A, Y162A, Y162A/H198P, and T167V/H198P DegS^ΔPDZ structures were aligned, and an average displacement for each Cα (CA) position in all pairwise combinations was calculated and plotted. High values represent regions that are disordered or have different conformations in different subunits. Low values represent regions that are very similar in all structures. C, average Cα (CA) displacements following alignment of 21 active subunits from the structures of wild-type DegS^ΔPDZ, DFP-modified DegS^ΔPDZ, and H198P DegS^ΔPDZ.