Chorismic acid
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 Script error: No such module "Lang". 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.
- File:Chorismate pathway 2.png
Metabolism
Chorismate is transformed into para-aminobenzoic acid by the enzymes 4-amino-4-deoxychorismate synthase and 4-amino-4-deoxychorismate lyase.Script error: No such module "Unsubst".
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.Script error: No such module "Unsubst".