MetaCyc Enzyme: 2-nitrophenol 2-monooxygenase

Species: Pseudomonas putida B2

2-nitrophenol 2-monooxygenase has been purified from Pseudomonas putida B2, a strain that is able to grow on 2-nitrophenol as the sole source of carbon and nitrogen [Zeyer84]. Experiments with a cell-free system showed that the enzyme is inducible by 2-nitrophenol, that the products were catechol and nitrite, and that NADPH is required. The specific activity in the cell-free system was 15 μmol/min/g protein [Zeyer84].

The enzyme was subsequently purified, and was shown to consist of a single polypeptide chain of 58 (gel filtration) or 65 (SDS-polyacrylamide gel) kDa [Zeyer88]. The enzyme was soluble, and consumed one molecule of molecular oxygen per molecule 2-nitrophenol converted.

Locations: cytosol

Molecular Weight of Polypeptide: 58.0 kD (experimental) [Zeyer88 ]

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Cellular Component: GO:0005829 - cytosol [Zeyer88]

Created 23-Aug-2007 by Caspi R , SRI International

Enzymatic reaction of: 2-nitrophenol 2-monooxygenase

EC Number:

2-nitrophenol + 2 NADPH + oxygen + 2 H+ <=> catechol + nitrite + 2 NADP+ + H2O

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the direction shown.

In Pathways: 2-nitrophenol degradation

Activators (Allosteric): Mg2+ [Zeyer88] , Mn2+ [Zeyer88]

Inhibitors (Competitive): 2,4-dinitrophenol [Zeyer88]

Kinetic Parameters:

Km (μM)

pH(opt): 7.5-8 [Zeyer88]


Zeyer84: Zeyer, J., Kearney, P. C. (1984). "Degradation of o-Nitrophenol and m-Nitrophenol by a Pseudomonas putida." J. Agric. Food Chem. 32: 238-242.

Zeyer88: Zeyer J, Kocher HP (1988). "Purification and characterization of a bacterial nitrophenol oxygenase which converts ortho-nitrophenol to catechol and nitrite." J Bacteriol 170(4);1789-94. PMID: 3350791

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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