Fig. 6. The GlnK protein affects the methylammonium transport activity of AmtB. [14C]methylammonium transport activities were determined as described in Materials and methods. Strains used were as follows. (A) ET8000, wild type (open circles); PT8000, ΔglnB (crosses); GT1002, ΔglnK (inverted trangles); and GT1000, ΔglnK amtB (filled circles). (B) YMC10, wild type (open circles); RB9060, ΔglnB (crosses); and WCH30, ΔglnK (inverted triangles). (C) ET8000, wild type (open circles); ET8000 (pWSK29), wild type (upright triangles); ET8000 (pTA40), wild type (pglnK+) (crosses); and ET8000 (pTA43), wild type (pglnKY51F) (diamonds). (D) ET8000, wild type (open circles); GT1000, ΔglnK amtB (filled circles); GT1000 (pGT11), ΔglnK amtB (glnK+ amtB+) (upright triangles); and GT1000 (pGT14), ΔglnK amtB (amtB+) (crosses).