σ/AsiA, σ/MotA, and AsiA/σ/MotA complexes
in native protein gels. The indicated σ was incubated with
excess His6AsiA and/or MotA and then subjected to electrophoresis
through native 6 % acrylamide gels as described in Materials and
Methods. The positions of σ, the σ/AsiA complex, the
σ/MotA complex, and the AsiA/σ/MotA complex are
shown. The positions of free MotA and AsiA are also marked. Excess free MotA
protein is the dark band that migrates near the top of the gel in the lanes
with added MotA. The excess free AsiA is usually not seen because AsiA is a
small protein (10 kDa) and stains poorly.