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 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 meaning "to separate", because the compound plays a role as a branch-point in aromatic amino acid biosynthesis.
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 C10H10O6 Isochorismic acid Salicylate synthase
References
External links Shikimate and chorismate biosynthesis