Evidence of allosteric alteration of CRPMt by cAMP. (A) SDS-PAGE of CRPMt after limited proteolysis with trypsin in the presence or absence of cAMP or AMP. M, molecular weight marker (Molecular Probes). CRPMt treatment was as follows: lanes 1 to 3, trypsin digestion; lanes 4 to 6, undigested controls; lanes 2 and 5, addition of 100 μM cAMP; lanes 3 and 6, supplementation with 100 μM AMP. (B) EMSA of CRPMt using intergenic Rv0884c-Rv0885 DNA probe after limited proteolysis with trypsin in the presence or absence of 100 μM cAMP or 100 μM AMP. The CRPMt treatment is shown at the top, with the digested CRPMt concentration indicated in mM. An EMSA with all samples was performed with 100 μM cAMP in the binding reaction buffer. The figure is representative of three experimental repeats.