TABLE 3.

Substrate specificity of the 3NP nitroreductase from R. eutropha JMP134

Substratea	Relative activity (%) in cell extracts of:
	R. eutropha JMP134b	P. putida B2c
Nitrobenzene	94	122
1,3-Dinitrobenzene	12	—d
1,3,5-Trinitrobenzene	21	—
2-Nitrophenol	62	106
3-Nitrophenol	100	100
4-Nitrophenol	18	33
2-Methyl-3-nitrophenol	25	—
4-Methyl-3-nitrophenol	15	—
2-Methyl-5-nitrophenol	98	—
4-Chloro-3-nitrophenol	52	—
2-Chloro-5-nitrophenol	114	—
2,3-Dinitrophenol	14	—
2,4-Dinitrophenol	<5	—
2,5-Dinitrophenol	53	—
2,6-Dinitrophenol	22	—
3,4-Dinitrophenol	6	—
3-Nitrocatechol	29	—
4-Nitrocatechol	<5	6
Nitrohydroquinone	<5	—
Picric acid	135	—
2-Nitrobenzoate	<5	10
3-Nitrobenzoate	70	83
4-Nitrobenzoate	81	67
2-Nitrotoluene	8	31
3-Nitrotoluene	95	—
4-Nitrotoluene	86	131
2,3-Dinitrotoluene	93	—
2,4-Dinitrotoluene	114	—
2,6-Dinitrotoluene	103	—
3,4-Dinitrotoluene	100	—
3-Nitroaniline	71	—
2-Amino-4-nitrotoluene	219	—
2-Amino-6-nitrotoluene	<10	—
3-Amino-4-nitrotoluene	<10	—
4-Amino-2-nitrotoluene	<10	—
4-Amino-3-nitrotoluene	<10	—
2,6-Diamino-4-nitrotoluene	20	—
2,4,6-Trinitrotoluene	99	—

^aThe substrate and NADPH were each provided at a 0.2 mM concentration. 

^bNADPH-oxidizing activities shown are relative to that of 3NP (taken as 100%) and varied between 73 and 157 U/g, depending on the induction state of the cells prior to harvesting. Activities were measured in extracts from 3NP-succinate-grown (induced) cells. Relative activities in the negative control (extracts from NH₄⁺–succinate-grown cells) never exceeded 6%. 

^cData were taken from Meulenberg et al. (31). An activity level of 100% corresponded to 120 U/g. The nitroaryl concentration was 0.1 mM. 

^d—, not determined.