TABLE 2.

Enhanced rates of oxidation of nitrophenols by the TouA E214 variants^a

Enzyme	Substrate
	o-Nitrophenol				p-Nitrophenol
	Prod- uct	Rateb	Rela- tive	Mol%	Prod- uct	Rateb	Rela- tive	Mol%
Wild-type ToMO	3-NC	0.12 ± 0.10	1.0	12	4-NC	0.0082 ± 0.0002	1.0	100
	NHQ	0.95 ± 0.15	1.0	88
E214G/ D312N/ M399V	3-NC	0.28	2.4	14	4-NC	0.164 ± 0.002	20	100
	NHQ	1.8	1.9	86
	E214G	3-NC	0.25 ± 0.01	2.1	12	4-NC	0.124 ± 0.004	15	100
	NHQ	1.9 ± 0.2	2.0	88
E214A	3-NC	0.19	1.6	14	4-NC	0.034 ± 0.001	4.3	100
	NHQ	1.2	1.3	86
E214V	3-NC	0.14	1.2	16	4-NC	0.011 ± 0.001	1.3	100
	NHQ	0.76	0.8	84
E214W	3-NC	0.038 ± 0.003	0.32	15	4-NC	0.0013 ± 0.0001	0.16	100
	NHQ	0.21 ± 0.01	0.22	85
E214Q	3-NC	0.12	1.0	12	NM	NM	NM	NM
	NHQ	0.86	0.9	88
E214F	3-NC	0.09	0.8	12	NM	NM	NM	NM
	NHQ	0.74	0.8	88

^ao-Nitrophenol and p-nitrophenol initial concentrations were 500 μM. NM, not measured; 3-NC, 3-nitrocatechol; NHQ, nitrohydroquinone; 4-NC, 4-nitrocatechol. Products were identified via HPLC.

^bInitial rate, in nanomoles per minute per milligram of protein.