FIG. 6.
Determination of cellular localization of GlnB, GlnK, and GlnY by Western blot analysis. Cytoplasmic (lanes 1 and 2) and membrane fractions (lanes 3 and 4) (20 μg of protein per lane) of Azoarcus sp. strain BH72 wild-type (A and B), strain BHGLKKBS (glnBK) (C), and strain BHABK (amtB) (D) grown on SM medium with 10 mM NH4Cl (lanes 1 and 3) or grown under conditions of nitrogen fixation on N-free SM medium (lanes 2 and 4) were analyzed using specific antisera against GlnK (A, D, and E), GlnB (B), and GlnY (C). (E) Membrane fractions of N2-fixing wild-type cells before (lane 1) and 15 min after (lane 2) ammonium switch-off.