Indole-3-glycerol phosphate synthase (IGPS); an enzyme in the tryptophan biosynthetic pathway, catalyzing the ring closure reaction of 1-(o-carboxyphenylamino)-1-deoxyribulose-5-phosphate (CdRP) to indole-3-glycerol phosphate (IGP), accompanied by the release of carbon dioxide and water. IGPS is active as a separate monomer in most organisms, but is also found fused to other enzymes as part of a bifunctional or multifunctional enzyme involved in tryptophan biosynthesis.
Structure:1LBL; Sulfolobus solfataricus IGPS with bound CdRP substrate; contacts at 3.5A
Comment:The IGPS active site consists of four subsites: the phosphate-binding site, the ribulose/triose-binding site, the anthranilate (substrate)- binding pocket and the indole (product)-binding pocket.
Jiyao W et al.(2023). "The conserved domain database in 2023.",