At pH 7 the measured Michaelis constant and maximum rate for the enzymatic conversion of fumarate to L-malate

fumarate + H2O --> L-malate

are 6.600 x 10-6 M and 1.200 x 103 [E]0 s-1 respectively, where [E]0 is the total molar concentration of the enzyme. The Michaelis constant and maximum velocity for the reverse reaction are 7.000 x 10-5 M and 590.000 [E]0 s-1. What is the equilibrium constant for the hydration reaction? (The activity of water is set to equal unity.)