(A) Summary of mutations isolated in A. aeolicus fliA. Domain regions correspond to regions shown in Fig. 1. Mutations resulting in single amino acid changes are listed in Table 2. (B) β-Galactosidase activities of fliC-lac in hybrid S. enterica serovar Typhimurium strains with A. aeolicus fliA mutants isolated defective for σ28/FlgM interactions. β-Galactosidase activities were compared to those of TH8125. Dark gray bars indicate the presence of FlgM; light gray bars indicate the absence of FlgM. Lane 1, WT (TH8125, TH8200); lane 2, P4S (TH8612, TH9607); lane 3, T27S (TH8613, TH9608); lane 4, I29M (TH8614, TH9609); lane 5, R149G (TH8615, TH9610); lane 6, T175M (TH8616, TH9611); lane 7, E189G (TH8617, TH9612); lane 8, E199G (TH8618, TH9647).