Fig. 5.

Sequence alignment of σ³² and FliA illustrates that the mutations define a cluster of surface-exposed residues. Regions 2.1 and 2.2 of Ec σ³² and Aa FliA were aligned (ClustalW; DNASTAR, Madison, WI). Residues corresponding to σ³² mutations were identified on the FliA structure (27) and mutated to the naturally occurring residues of σ³² (asterisks) in PyMOL. Shown are Arg¹¹ mutated to Ala (Ala⁵⁰ in σ³²; red), Glu¹² mutated to Lys (Lys⁵¹ in σ³²; pink), Ile¹⁵ (Ile⁵⁴ in σ³²; blue), and Asp⁵⁵ mutated to Arg (Arg⁹¹ in σ³²; green). These residues form a surface-exposed patch.