Chorismic acid, more commonly known as its anionic form chorismate, is an important biochemical intermediate in plants and microorganisms. It is a precursor for:
- The aromatic amino acids phenylalanine, tryptophan, and tyrosine
- Indole, indole derivatives and tryptophan
- 2,3-Dihydroxybenzoic acid (DHB) used for enterobactin biosynthesis
- The plant hormone salicylic acid[1]
- Many alkaloids and other aromatic metabolites.
- The folate precursor para-aminobenzoate (pABA)
- The biosynthesis of vitamin K and folate in plants and microorganisms.
The name chorismic acid derives from a classical Greek word χωρίζω meaning "to separate",[2] because the compound plays a role as a branch-point in aromatic amino acid biosynthesis.[3]
Biosynthesis
Shikimate → shikimate-3-phosphate → 5-enolpyruvylshikimate-3-phosphate (5-O-(1-carboxyvinyl)-3-phosphoshikimate)
Chorismate synthase is an enzyme that catalyzes the final chemical reaction:
- 5-O-(1-carboxyvinyl)-3-phosphoshikimate → chorismate + phosphate.
Metabolism
Chorismate is transformed into para-aminobenzoic acid by the enzymes 4-amino-4-deoxychorismate synthase and 4-amino-4-deoxychorismate lyase.
Chorismate lyase is an enzyme that transforms chorismate into 4-hydroxybenzoate and pyruvate. This enzyme catalyses the first step in ubiquinone biosynthesis in Escherichia coli and other Gram-negative bacteria.
See also
References
- ^ Wildermuth MC, Dewdney J, Wu G, Ausubel FM (2001). "Isochorismate synthase is required to synthesize salicylic acid for plant defence". Nature. 414 (6863): 562–5. Bibcode:2001Natur.414..562W. doi:10.1038/35107108. PMID 11734859.
- ^ Henry George Liddell; Robert Scott; Henry Stuart Jones & Roderick McKenzie. A Greek-English Lexicon. ISBN 0-19-864226-1.
- ^ Gibson, F. (1999). "The elusive branch-point compound of aromatic amino acid biosynthesis". Trends in Biochemical Sciences. 24 (1): 36–38. doi:10.1016/S0968-0004(98)01330-9. PMID 10087921.
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