Steady-state kinetics of wild-type and mutant R510Q RPK in the presence of ATP.

(A) Steady-state kinetics of recombinant wild-type (circles) and R510Q mutant (squares) RPK as a function of PEP in the presence of 1.5 mM ATP (filled symbols). Open symbols are data points obtained in the presence of 1.5 mM ATP plus 30 μM FBP. (B) Semilog plot of the data in panel A to show the difference between the wild-type and mutant protein at physiologic concentration of PEP (shaded box).