FIGURE 1.

CgAcr3 transports and confers resistance to arsenite but not antimonite. Resistance and transport were assayed as described under “Experimental Procedures.” Assays were performed with E. coli AW3110 (Δars) bearing the following plasmids: ●, vector plasmid pKK223-3; ○, pKMB1 (arsB); ▼, pTrcHis2A-CgAcr3-His (Cgacr3). Resistance to the indicated concentrations of sodium arsenite (A) or potassium antimonyl tartrate (C) is shown. Accumulation of As(III) (B) or Sb(III) (D) was assayed. B and D, error bars represent the S.D. of three assays.