Accepted name: 3-amino-4-hydroxybenzoate synthase
Reaction: 2-amino-4,5-dihydroxy-6-oxo-7-(phosphooxy)heptanoate = 3-amino-4-hydroxybenzoate + phosphate + 2 H2O
Other name(s): 3,4-AHBA synthase; griH (gene name)
Systematic name: 2-amino-4,5-dihydroxy-6-oxo-7-(phosphooxy)heptanoate hydro-lyase (cyclizing, 3-amino-4-hydroxybenzoate-forming)
Comments: Requires Mn2+ for maximum activity. The reaction is suggested to take place in several steps. Schiff base formation, double bond migration and dephosphorylation followed by ring opening and closing to form a pyrrolidine ring, and finally dehydration to form the product 3-amino-4-hydroxybenzoate. In the bacterium Streptomyces griseus the enzyme is involved in biosynthesis of grixazone, a yellow pigment that contains a phenoxazinone chromophore.
1.  Suzuki, H., Ohnishi, Y., Furusho, Y., Sakuda, S. and Horinouchi, S. Novel benzene ring biosynthesis from C3 and C4 primary metabolites by two enzymes. J. Biol. Chem. 281 (2006) 36944–36951. [PMID: 17003031]
[EC created 2013, modified 2016]