IUBMB Enzyme Nomenclature


Accepted name: tetracycline 7-halogenase

Reaction: tetracycline + FADH2 + chloride + O2 + H+ = 7-chlorotetracycline + FAD + 2 H2O

For diagram of reaction click here.

Other name(s): ctcP (gene name)

Systematic name: tetracycline:FADH2 oxidoreductase (7-halogenating)

Comments: The enzyme, characterized from the bacterium Streptomyces aureofaciens, is a member of the flavin-dependent halogenase family. The enzyme forms a lysine chloramine intermediate on an internal lysine residue before transferring the chlorine to the substrate. It is stereo-selective for the 4S (natural) isomer of tetracycline. FADH2 is provided by a dedicated EC, flavin reductase (NADH).

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


1. Dairi, T., Nakano, T., Aisaka, K., Katsumata, R. and Hasegawa, M. Cloning and nucleotide sequence of the gene responsible for chlorination of tetracycline. Biosci. Biotechnol. Biochem. 59 (1995) 1099-1106. [PMID: 7612997]

2. Zhu, T., Cheng, X., Liu, Y., Deng, Z. and You, D. Deciphering and engineering of the final step halogenase for improved chlortetracycline biosynthesis in industrial Streptomyces aureofaciens. Metab. Eng. 19 (2013) 69-78. [PMID: 23800859]

[EC created 2016]

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