|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions → Composite Reactions|
|Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Mass balance status: Balanced.
Enzyme Commission Primary Name: tryptophan synthase
Enzyme Commission Synonyms: L-tryptophan synθse, indoleglycerol phosphate aldolase, tryptophan desmolase, tryptophan synθse, L-serine hydro-lyase (adding indoleglycerol-phosphate), L-serine hydro-lyase [adding 1-C-(indol-3-yl)glycerol 3-phosphate, L-tryptophan and glyceraldehyde-3-phosphate-forming]
Enzyme Commission Summary:
A pyridoxal-phosphate protein. The α-subunit catalyses the conversion of 1-C-(indol-3-yl)glycerol 3-phosphate to indole and glyceraldehyde 3-phosphate (this reaction was listed formerly as EC 22.214.171.124). The indole migrates to the β-subunit where, in the presence of pyridoxal 5'-phosphate, it is combined with L-serine to form L-tryptophan. In some organisms this enzyme is part of a multifunctional protein that also includes one or more of the enzymes EC 126.96.36.199 (anthranilate phosphoribosyltransferase), EC 188.8.131.52 (indole-3-glycerol-phosphate synthase), EC 184.108.40.206 (anthranilate synthase) and EC 220.127.116.11 (phosphoribosylanthranilate isomerase). In thermophilic organisms, where the high temperature enhances diffusion and causes the loss of indole, a protein similar to the α subunit can be found (EC 18.104.22.168). That enzyme cannot combine with the β unit of EC 22.214.171.124 to form a complex.
Hyde88: Hyde CC, Ahmed SA, Padlan EA, Miles EW, Davies DR (1988). "Three-dimensional structure of the tryptophan synthase alpha 2 beta 2 multienzyme complex from Salmonella typhimurium." J Biol Chem 263(33);17857-71. PMID: 3053720
Woehl99: Woehl E, Dunn MF (1999). "Mechanisms of monovalent cation action in enzyme catalysis: the tryptophan synthase alpha-, beta-, and alpha beta-reactions." Biochemistry 38(22);7131-41. PMID: 10353823
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