Tryptophan synthase
FunctionTryptophan synthase (TrpS) is an α2β2 tetramer participating in the biosynthesis of tryptophan (Trp)[1]. TrpS α subunit catalyzes the formation of indole and glyceraldehyde-3-phosphate (G3P) from indole-3-glycerol phosphate (IGP). The β subunit catalyzes in a pyridoxal-phosphate (PLP) dependent reaction the formation of tryptophan (Trp) from indole and serine. The diffusion of indole from the α to the β subunit is facilitated via a hydrophobic channel connecting the subunits. Dimethylallyl tryptophan synthase (DMTS) catalyzes the alkylation of Trp by dimethylallyl phosphate to form 4-(γ,γ-dimethylallyl)-Trp[2]. RelevanceTrpS is not found in animals hence it is tested as a possible drug target for tuberculosis, ocular and genital infections, cryptosporidiosis and as herbicide[3]. Structural highlightsThe of TrpS subunit α contains the catalytic residues Glu and Asp[4]. Water molecules are shown as red spheres. 3D structures of tryptophan synthaseTryptophan synthase 3D structures
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ReferencesReferences
- ↑ Miles EW. Tryptophan synthase: a multienzyme complex with an intramolecular tunnel. Chem Rec. 2001;1(2):140-51. PMID:11893063
- ↑ Gebler JC, Poulter CD. Purification and characterization of dimethylallyl tryptophan synthase from Claviceps purpurea. Arch Biochem Biophys. 1992 Jul;296(1):308-13. PMID:1605639 doi:10.1016/0003-9861(92)90577-j
- ↑ Shen H, Yang Y, Wang F, Zhang Y, Ye N, Xu S, Wang H. Characterization of the putative tryptophan synthase beta-subunit from Mycobacterium tuberculosis. Acta Biochim Biophys Sin (Shanghai). 2009 May;41(5):379-88. PMID:19430702
- ↑ Kulik V, Hartmann E, Weyand M, Frey M, Gierl A, Niks D, Dunn MF, Schlichting I. On the structural basis of the catalytic mechanism and the regulation of the alpha subunit of tryptophan synthase from Salmonella typhimurium and BX1 from maize, two evolutionarily related enzymes. J Mol Biol. 2005 Sep 23;352(3):608-20. PMID:16120446 doi:10.1016/j.jmb.2005.07.014