Reaction: (1S,2R)-1-C-(indol-3-yl)glycerol 3-phosphate = indole + D-glyceraldehyde 3-phosphate
For diagram click here.
Other name(s): tryptophan synthase α; TSA; indoleglycerolphosphate aldolase; indole glycerol phosphate hydrolase; indole synthase; indole-3-glycerolphosphate D-glyceraldehyde-3-phosphate-lyase; indole-3-glycerol phosphate lyase; IGL; BX1; (1S,2R)-1-C-(indol-3-yl)glycerol 3-phosphate D-glyceraldehyde-3-phosphate-lyase
Systematic name: (1S,2R)-1-C-(indol-3-yl)glycerol 3-phosphate D-glyceraldehyde-3-phosphate-lyase (indole-forming)
Comments: Forms part of the defence mechanism against insects and microbial pathogens in the grass family, Gramineae, where it catalyses one of the steps in the formation of the cyclic hydroxamic acids 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA) and 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) [1]. This enzyme resembles the α-subunit of EC 4.2.1.20, tryptophan synthase [3] but, unlike tryptophan synthase, its activity is independent of the β-subunit and free indole is released [2].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9014-52-2
References:
1. Yanofsky, C. The enzymatic conversion of anthranilic acid to indole. J. Biol. Chem. 223 (1956) 171-184. [PMID: 13376586]
2. Frey, M., Chomet, P., Glawischnig, E., Stettner, C., Grün, S., Winklmair, A., Eisenreich, W., Bacher, A., Meeley, R.B., Briggs, S.P., Simcox, K. and Gierl, A. Analysis of a chemical plant defense mechanism in grasses. Science 277 (1997) 696-699.
3. Frey, M., Stettner, C., Paré, P.W., Schmelz, E.A., Tumlinson, J.H. and Gierl, A. An herbivore elicitor activates the gene for indole emission in maize. Proc. Natl. Acad. Sci. USA 97 (2000) 14801-14806. [PMID: 11106389]
4. Melanson, D., Chilton, M.D., Masters-Moore, D. and Chilton, W.S. A deletion in an indole synthase gene is responsible for the DIMBOA-deficient phenotype of bxbx maize. Proc. Natl. Acad. Sci. USA 94 (1997) 13345-13350. [PMID: 9371848]