Phloroglucinol synthase
Phloroglucinol synthase is an acetyltransferase enzyme involved in the synthesis of phloroglucinol, a pharmaceutically and industrially important benzentriol molecule used in medicines and explosives. The enzyme, as taken from the bacterium pseudomonas protegens, is a type III polyketide synthase. The enzyme cyclizes the activated form of 3,5-dioxoheptanedioate.
Phloroglucinol synthase exhibits broad substrate specificity, able to accept C4-C12 aliphatic acyl-CoAs and phenylacetyl-CoAs, yielding polyoxoalkylated alpha-pyrones by condensation with malonyl-CoA. The enzyme catalyzes the following reaction,
It was shown that the kcat for this enzyme was 10 min-1. Its product, phloroglucinol is used in industry as well as in the synthesis of pharmaceuticals. It can be used to make phloroglucinol but it shows low productivity.