L-tryptophan synthase

Indoleglycerol 3-phosphate (13) is converted into tryptophan (14) by the action of L-tryptophan synthase. The mechanism of this enzymatic reaction involves formation of a Schiff base with an enzyme-bound pyridoxal phosphate. The a-aminoacrylate Schiff base formed undergoes the addition of a p-substituent to produce tryptophan (Floss, 1986) (Fig. 7.5). 

L-Tryptophan synthase, tryptophan desmolase, L-serine hydro-lyase (adding imhleglycerol-phos-phate) (EC 4.2.1.20) the enzyme catalysing the synthesis of L-tryptophan from L-serine and indole 3-glycerol phosphate. T.s. from E. coli (M, 149,000) and other prokaryotes has 02 subunit composition. The enzyme separates easily into monomeric subunit a (also called protein B, M, 29,000) and dimeric subunit 02 (also called protein B Af, of dimer 90,000) when eluted from DEAE cellulose with a sodium chloride gradient. The separated subunits catalyse partial reactions of L-tryptophan synthesis ... 

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