Figure 6: The activities of SeHAS triple Cys-mutants are differentially affected by Cu2+. Membranes containing SeHAS wildtype or triple Cysmutants were incubated in the presence of 20 mM MgCl2 and the indicated concentrations of CuCl2 and HA synthase activity was determined as described in Methods. The SeHAS variants (with the single free Cys indicated) were: wildtype, red circle; Δ3C(C226), green square; Δ3C(C262), dark blue triangle; Δ3C(C281), yellow inverted triangle; Δ3C(C367), light blue diamond.