FIG. 7.
Reaction of purified CL-F386C AcrBHis mutants with the fluorescence probe MIANS. MIANS labeling was carried out with 0.5 μM purified protein in 2 ml of 20 mM HEPES-KOH (pH 7.5)-50 mM NaCl-0.02% dodecyl maltoside. Reactions were initiated by the addition of MIANS to a final concentration of 5 μM, and the fluorescence increase was recorded continuously at 430 nm (excitation, 330 nm). Mutants were as follows: 1, CL-F386C; 2, CL386-N109A; 3, CL386-D407A; 4, CL386-D408A; 5, CL386-K940A; and 6, CL386-T978A.