EC - Carnitine monooxygenase

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IntEnz Enzyme Nomenclature


Accepted name:
carnitine monooxygenase
Other names:
cntAB (gene names)
yeaWX (gene names)
Systematic name:
L-carnitine,NAD(P)H:oxygen oxidoreductase (trimethylamine-forming)



The bacterial enzyme is a complex consisting of a reductase and an oxygenase components. The reductase subunit contains a flavin and a plant-type ferredoxin [2Fe-2S] cluster, while the oxygenase subunit is a Rieske-type protein in which a [2Fe-2S] cluster is coordinated by two histidine and two cysteine residues.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB


  1. Ditullio, D., Anderson, D., Chen, C. S., Sih, C. J.
    L-carnitine via enzyme-catalyzed oxidative kinetic resolution.
    Bioorg. Med. Chem. 2 : 415-420 (1994). [PMID: 8000862]
  2. Zhu, Y., Jameson, E., Crosatti, M., Schafer, H., Rajakumar, K., Bugg, T. D., Chen, Y.
    Carnitine metabolism to trimethylamine by an unusual Rieske-type oxygenase from human microbiota.
    Proc. Natl. Acad. Sci. U.S.A. 111 : 4268-4273 (2014). [PMID: 24591617]
  3. Koeth, R. A., Levison, B. S., Culley, M. K., Buffa, J. A., Wang, Z., Gregory, J. C., Org, E., Wu, Y., Li, L., Smith, J. D., Tang, W. H., DiDonato, J. A., Lusis, A. J., Hazen, S. L.
    gamma-Butyrobetaine is a proatherogenic intermediate in gut microbial metabolism of L-carnitine to TMAO.
    Cell Metab. 20 : 799-812 (2014). [PMID: 25440057]

[EC created 2017]