FIG 6.

Phosphorylation of HPr by 50 ng of EI^Ntr in the presence of α-ketoglutarate. (A) α-Ketoglutarate does not stimulate EI^Ntr activity. Lane 1, no EI^Ntr; lane 2, no HPr; lane 3, no PEP; lane 4, full reaction mixture with 500 ng of EI^Ntr; lanes 5 to 10, reaction mixtures contained the indicated amounts of α-ketoglutarate or glutamine (in mM). (B) α-Ketoglutarate does not compete with glutamine to relieve EI^Ntr inhibition. Lanes 1 to 4, same reaction mixtures as in panel A; lanes 5 to 10, reaction mixtures contained the indicated concentrations of α-ketoglutarate and glutamine (in mM).