| EC |
4.2.1.122 |
| Accepted name: |
tryptophan synthase (indole-salvaging) |
| Reaction: |
L-serine + indole = L-tryptophan + H2O |
| Other name(s): |
tryptophan synthase β2 |
| Systematic name: |
L-serine hydro-lyase [adding indole, L-tryptophan-forming] |
| Comments: |
Most mesophilic bacteria have a multimeric tryptophan synthase complex (EC 4.2.1.20) 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 4.2.1.20. |
| Links to other databases: |
BRENDA, EXPASY, Gene, KEGG, MetaCyc |
| References: |
| 1. |
Hettwer, S. and 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 (2002) 8194–8201. [DOI] [PMID: 11756459] |
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| [EC 4.2.1.122 created 2011] |
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