Figure 1.

The biochemical pathway of tryptophan biosynthesis. The genetic nomenclature for the seven genes that encode the enzymes is that for Bacillus subtilis. PR-Anth, N-(5'-phosphoribosyl)-anthranilate; CdRP, 1-(o-carboxy-phenylamino)-1-deoxyribulose-5-phosphate; InGP, indole 3-glycerol phosphate. trpE encodes the large aminase subunit of anthranilate synthase; trpG encodes for small glutamine binding subunit of anthranilate synthase and catalyzes the glutaminase reaction; trpD encodes anthranilate-phosphoribosyl transferase; trpF encodes phosphoribosyl-anthranilate isomerase; trpC encodes indoleglycerol phosphate synthase; trpA, the a subunit of tryptophan synthase which converts InGP to indole; trpB encodes the b subunit of tryptophan synthase and converts indole and serine to tryptophan and glyceraldehydes-3-phosphate.