IUBMB Enzyme Nomenclature


Accepted name: L-threonyl-[L-threonyl-carrier protein] 4-chlorinase

Reaction: an L-threonyl-[L-threonyl-carrier protein] + 2-oxoglutarate + O2 + Cl- = a 4-chloro-L-threonyl-[L-threonyl-carrier protein] + succinate + CO2 + H2O

Other name(s): syrB2 (gene name)

Systematic name: L-threonyl-[L-threonyl-carrier protein],2-oxoglutarate:oxygen oxidoreductase (4-halogenating)

Comments: The enzyme, characterized from the bacterium Pseudomonas syringae, participates in syringomycin E biosynthesis. The enzyme is a specialized Fe(II)/2-oxoglutarate-dependent oxygenase that catalyses the chlorination of its substrate in a reaction that requires oxygen, chloride ions, ferrous iron and 2-oxoglutarate.

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


1. Vaillancourt, F.H., Yin, J. and Walsh, C.T. SyrB2 in syringomycin E biosynthesis is a nonheme FeII α-ketoglutarate- and O2-dependent halogenase. Proc. Natl Acad. Sci. USA 102 (2005) 10111-10116. [PMID: 16002467]

[EC created 2018]

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