(A) Motility assay of S. enterica serovar Typhimurium fliA-defective strain TH4387 with the following plasmids: vector (pBAD24), ParaB-σ28 S. enterica serovar Typhimurium (S.t.) (pMC147), ParaB-σ28 A. aeolicus (A.a.) (pJK558), and ParaB-σ28 C. trachomatis (C.t.) (pJK629). (B) Western analysis of total cellular proteins from S. enterica serovar Typhimurium hybrid strains fliA (σ28) from A. aeolicus and C. trachomatis probing with anti-FliC antiserum. Lane 1, TH437 (S. enterica serovar Typhimurium wild-type strain LT2); lane 2, TH6827 (ΔfliA5805::tetRA); lane 3, TH8142 ((fliA6068 [A. aeolicus fliA]); lane 4, TH8982 ((fliA6325 [C. trachomatis rspD]). Fourfold more cellular lysate was loaded in lanes 2 to 4 than in lane 1.