Figure 5.
(A) SecAΔC and derivatives (0.9 mg/ml in buffer B) were treated with trypsin (25 μg/ml; 4°C; 13 min) in the absence or presence of ADP (1mM) (as indicated) or a three-fold molar excess of C34 (wherever indicated). Following SDS–PAGE, polypeptides were immunostained by α-IRA2-specific antibody. (B) Basal ATPase activities of SecA, SecA(R566A) and SecA(R347A) (as in Figure 1C). (C) Equilibrium dissociation constants (Kd) of SecA and SecA(R566A) for MANT-ADP plotted as a function of temperature. Two curves (dotted lines) from Figure 4D are included for comparison.