Table 1. Effect of Mutations of Phosphodianion Gripper Amino Acid Residues on the Kinetic Parameters for ScOMPDC-Catalyzed Decarboxylation of FOMP^a.

ScOMPDC	kcat (s–1)b	(kcat)F/(kcat)Hh	Km (M)b	kcat/Km (M–1 s–1)	(kcat/Km)F/(kcat/Km)Hh
wild-typec	95	6	8 × 10–6	1.2 × 107	1.1
Q215Ad	190 ± 10	8	(9.6 ± 1) × 10–5	2.0 × 106	8
Y217Fd	430 ± 30	21	(4.2 ± 0.6) × 10–4	1.1 × 106	6
R235c	92	92	5.8 × 10–4	1.6 × 105	180
Q215A/Y217Fd	49 ± 5	10	(9.2 ± 1.7) × 10–4	5.3 × 104	16
Q215A/R235Ae	4.7 ± 0.3	240	(6.5 ± 0.8) × 10–4	7200	500
Y217F/R235Ae				820	200
triple mutant				28	760
S154Af	16 ± 0.5	200i	(5.5 ± 0.6) × 10–5	2.9 × 105	460i
S154A/Q215Af	6.6 ± 0.3	160i	(8.6 ± 1.3) × 10–5	7.7 × 104	200i
Y217Ag	8.2 ± 0.5	2g	(6.2 ± 0.6) × 10–4	1.3 × 104	5g

^aFor reactions at pH 7.1 (30 mM MOPS), 25 °C, and I = 0.105 (NaCl).

^bThe quoted errors are the standard deviations obtained from the nonlinear least-squares fits of data from panels A–C of Figure 3 to the Michaelis–Menten equation.

^cFrom ref (29).

^dFigure 3A.

^eFigure 3B.

^fFigure 3C.

^gKinetic parameters for reactions of OMP from ref (37).

^hKinetic parameters for reactions of OMP from ref (19), unless indicated otherwise.

ⁱKinetic parameters for reactions of OMP from ref (34).