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 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 χωρίζω 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
Chorismate synthase is an enzyme that catalyzes the final chemical reaction:

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.