FIG. 2.

yopD and lcrH are required for the function of YscM1 and YscM2. Y. enterocolitica strains were analyzed for type III secretion as described in the legend to Fig. 1. (A) Y. enterocolitica strains W22703 (wild type), VTL2 [Δ(yopD)], CT133 [Δ(lcrH)], and EC2 [Δ(yscM1 yscM2)] were analyzed by immunoblotting with antisera raised against purified YscM1, YscM2, YopD, LcrH, and YscD. The type III machinery component YscD is located within bacteria. (B) Y. enterocolitica W22703 (wild type) harboring pDA259 (encoding Gst), pEC345 (encoding YscM1), or pEC348 (encoding YscM2) were cultured in −Ca²⁺. Plasmid-borne genes were overexpressed (⁺⁺) by adding 1 mM IPTG when shifting the temperature of bacterial cultures to induce the type III virulon. (C) Yersinia strains VTL2 [Δ(yopD)] and CT133 [Δ(lcrH)] were transformed with pEC345 and pEC348 and analyzed by immunoblotting.