FIG. 5.
Western immunoblots of GlnB in UR2 (wild type) and UR2187 (purE mutant). Cells were grown in MG medium with 0.1 mM adenine for about 2 days, with OD600 at 2.0 to 2.5. Then, 1-ml portions of the same culture were rapidly extracted by TCA precipitation of derepressed cultures of UR2 and UR2187 (lane 1), 60 min after a shift to dark (lane 2), and 10 min after a return to light (lane 3). Protein samples were loaded on low cross-linker SDS-Tricine gels and immunoblotted with antibody to R. rubrum GlnB. Arrow M indicates the position of the modified subunit, and arrow U indicates the position of the unmodified subunit.