Analysis of EspA kinase activity. (A) Autoradiograph of GST-EspAkin (lane 1), GST-EspAkin(H407A) (lane 2), GST-EspAkin-rec (lane 3), and GST-EspAkin-rec(D696A) (lane 4) incubated in the presence of [γ-32P]ATP. (B) Coomassie-stained gel corresponding to panel A. (C) TLC analysis of [α-32P]ADP produced by [α-32P]ATP (lane 1), GST-EspAkin (lane 2), GST-EspAkin-rec (lane 3), and GST-EspAkin-rec(D696A) (lane 4). (D) Quantification of [α-32P]ADP signal in panel C as an average from triplicate experiments.