FIGURE 2.

A, 11-state reversible catalytic mechanism adapted from Rose et al. (6), accounting for the isomechanism for enzyme recycling with first-order rate constants. Subscripts f and m denote fumarate and malate specificity, respectively. Dashed line boxes indicate states that are lumped through quasi-equilibrium assumptions. Dead end competitive binding of fumarate and phosphate are not represented. B, six-state model obtained from applying quasi-equilibrium assumptions to the 11-state model in A.