FIGURE 3.
Effect of thiol-modifying reagents on arsenite uptake by CgAcr3. Arsenite accumulation was assayed as described under “Experimental Procedures” in EDTA-treated cells of AW3110 expressing the following: ●, vector plasmid pTrcHis2A; ○, pKMB1 (arsB); ▼, pTrcHis2A-CgAcr3-His (Cgacr3); and Δ, pCgAcr3C141S-His with the following additions: A, no addition; B, 1 mm 5,5′-dithiobis-(2-nitrobenzoic acid); C, 0.2 mm p-chloromercuribenzenesulfonate; and D, 1 mm N-ethylmaleimide. The error bars represent the S.D. of three assays.