| EC |
1.14.19.9 |
| Accepted name: |
tryptophan 7-halogenase |
| Reaction: |
L-tryptophan + FADH2 + chloride + O2 + H+ = 7-chloro-L-tryptophan + FAD + 2 H2O |
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For diagram of chlorotryptophan biosynthesis, click here |
| Other name(s): |
prnA (gene name); rebH (gene name); ktzQ (gene name) |
| Systematic name: |
L-tryptophan:FADH2 oxidoreductase (7-halogenating) |
| Comments: |
A flavin-dependent halogenase. The enzyme from the bacterium Lechevalieria aerocolonigenes catalyses the initial step in the biosynthesis of rebeccamycin [2]. It utilizes molecular oxygen to oxidize the FADH2 cofactor, giving C4a-hydroperoxyflavin, which then reacts with chloride to produce a hypochlorite ion. The latter reacts with an active site lysine to generate a chloramine, which chlorinates the substrate. Also acts on bromide ion. cf. EC 1.14.19.58, tryptophan 5-halogenase, and EC 1.14.19.59, tryptophan 6-halogenase. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
| References: |
| 1. |
Dong, C., Kotzsch, A., Dorward, M., van Pee, K.H. and Naismith, J.H. Crystallization and X-ray diffraction of a halogenating enzyme, tryptophan 7-halogenase, from Pseudomonas fluorescens. Acta Crystallogr. D Biol. Crystallogr. 60 (2004) 1438–1440. [DOI] [PMID: 15272170] |
| 2. |
Yeh, E., Garneau, S. and Walsh, C.T. Robust in vitro activity of RebF and RebH, a two-component reductase/halogenase, generating 7-chlorotryptophan during rebeccamycin biosynthesis. Proc. Natl. Acad. Sci. USA 102 (2005) 3960–3965. [DOI] [PMID: 15743914] |
| 3. |
Bitto, E., Huang, Y., Bingman, C.A., Singh, S., Thorson, J.S. and Phillips Jr., G.N. The structure of flavin-dependent tryptophan 7-halogenase RebH. Proteins Struct. Funct. Genet. 70 (2008) 289–293. [DOI] [PMID: 17876823] |
| 4. |
Heemstra, J.R., Jr. and Walsh, C.T. Tandem action of the O2- and FADH2-dependent halogenases KtzQ and KtzR produce 6,7-dichlorotryptophan for kutzneride assembly. J. Am. Chem. Soc. 130 (2008) 14024–14025. [DOI] [PMID: 18828589] |
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| [EC 1.14.19.9 created 2009 as EC 1.14.14.7, transferred 2014 to EC 1.14.19.9, modified 2018] |
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