IUBMB Enzyme Nomenclature


Accepted name: toluene 4-monooxygenase

Reaction: toluene + NADH + H+ + O2 = 4-methylphenol + NAD+ + H2O

Glossary: 4-methylphenol = p-cresol

Other name(s): TMO

Systematic name: toluene,NADH:oxygen oxidoreductase (4-hydroxylating)

Comments: This bacterial enzyme belongs to a family of soluble diiron hydroxylases that includes toluene-, benzene-, xylene- and methane monooxygenases, phenol hydroxylases, and alkene epoxidases. The enzyme comprises a four-component complex that includes a hydroxylase, NADH-ferredoxin oxidoreductase, a Rieske-type [2Fe-2S] ferredoxin, and an effector protein.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Whited, G.M. and Gibson, D.T. Toluene-4-monooxygenase, a three-component enzyme system that catalyzes the oxidation of toluene to p-cresol in Pseudomonas mendocina KR1. J. Bacteriol. 173 (1991) 3010-3016. [PMID: 2019563]

2. Hemmi, H., Studts, J.M., Chae, Y.K., Song, J., Markley, J.L. and Fox, B.G. Solution structure of the toluene 4-monooxygenase effector protein (T4moD). Biochemistry 40 (2001) 3512-3524. [PMID: 11297417]

3. Schwartz, J.K., Wei, P.P., Mitchell, K.H., Fox, B.G. and Solomon, E.I. Geometric and electronic structure studies of the binuclear nonheme ferrous active site of toluene-4-monooxygenase: parallels with methane monooxygenase and insight into the role of the effector proteins in O2 activation. J. Am. Chem. Soc. 130 (2008) 7098-7109. [PMID: 18479085]

4. Bailey, L.J., Acheson, J.F., McCoy, J.G., Elsen, N.L., Phillips, G.N., Jr. and Fox, B.G. Crystallographic analysis of active site contributions to regiospecificity in the diiron enzyme toluene 4-monooxygenase. Biochemistry 51 (2012) 1101-1113. [PMID: 22264099]

5. Hosseini, A., Brouk, M., Lucas, M.F., Glaser, F., Fishman, A. and Guallar, V. Atomic picture of ligand migration in toluene 4-monooxygenase. J. Phys. Chem. B 119 (2015) 671-678. [PMID: 24798294]

[EC created 2017]

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