Fig. 3.

AbbA binds AbrB. A shows affinity chromatography of AbrB using immobilized His₆-AbbA. Lysates prepared from exponentially growing wild-type cells (PY79) were incubated with purified His₆-AbbA (Left and Right) or His₆-SinR (Center) and applied to a Ni²⁺NTA-agarose column. The presence of AbrB, σ^A, His₆-AbbA and His₆-SinR was monitored in the load (L), flow-through (FT), wash (W) and eluate (E) by immunoblotting using specific antibodies (Left and Center) or Coomassie staining (Right). Benchmark prestained protein ladder (Invitrogen) is shown in the far left lane of the Coomassie-stained gel (Right). Elution fractions were concentrated 2.5-fold relative to the load. B shows affinity chromatography of AbbA using immobilized His₆-AbrB. Purified AbbA was incubated with purified His₆-AbrB or His₆-SinR and applied to Ni²⁺NTA-agarose. The presence of AbbA, His₆-AbrB, and His₆-SinR was detected in the load (L), flow-through (FT), wash (W) and elution (E) fractions by Coomassie staining. Elution fractions were concentrated 10-fold relative to the load.