EC - Tryptophan synthase (indole-salvaging)

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IntEnz Enzyme Nomenclature


Accepted name:
tryptophan synthase (indole-salvaging)
Other name:
tryptophan synthase β2
Systematic name:
L-serine hydro-lyase [adding indole, L-tryptophan-forming]



Most mesophilic bacteria have a multimeric tryptophan synthase complex (EC that forms L-tryptophan from L-serine and 1-C-(indol-3-yl)glycerol 3-phosphate via an indole intermediate. This intermediate, which is formed by the α subunits, is transferred in an internal tunnel to the β units, which convert it to tryptophan. In thermophilic organisms the high temperature enhances diffusion and causes the loss of indole. This enzyme, which does not combine with the α unit to form a complex, salvages the lost indole back to L-tryptophan. It has a much lower Km for indole than the β subunit of EC

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0052684


  1. Hettwer, S., Sterner, R.
    A novel tryptophan synthase β-subunit from the hyperthermophile Thermotoga maritima. Quaternary structure, steady-state kinetics, and putative physiological role.
    J. Biol. Chem. 277 : 8194-8201 (2002). [PMID: 11756459]

[EC created 2011]