Chorismate

Chorismic acid, more commonly known as its ion, 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 4-Aminobenzoic acid, (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.{{Cite journal , last1 = Gibson , first1 = F. , title = The elusive branch-point compound of aromatic amino acid biosynthesis , doi = 10.1016/S0968-0004(98)01330-9 , journal = Trends in Biochemical Sciences , volume = 24 , issue = 1 , pages = 36–38 , year = 1999 , pmid = 10087921

Biosynthesis

Shikimic acid, 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, 5-''O''-(1-carboxyvinyl)-3-phosphoshikimate → chorismate + phosphate.
:

Metabolism

Chorismate is transformed into ''para''-aminobenzoic acid by the enzymes Aminodeoxychorismate synthase, 4-amino-4-deoxychorismate synthase and Aminodeoxychorismate lyase, 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, C₁₀H₁₀O₆
* Salicylate synthase

References

External links

Shikimate and chorismate biosynthesis

Cyclohexadienes
Dicarboxylic acids
Secondary alcohols
Ethers