cd06446

Tryptophan synthase-beta: Trptophan synthase is a bifunctional enzyme that catalyses the last two steps in the biosynthesis of L-tryptophan via its alpha and beta reactions. In the alpha reaction, indole 3-glycerol phosphate is cleaved reversibly to glyceraldehyde 3-phosphate and indole at the active site of the alpha subunit. In the beta reaction, indole undergoes a PLP-dependent reaction with L-serine to form L-tryptophan at the active site of the beta subunit. Members of this CD, Trp-synth_B, are found in all three major phylogenetic divisions.