  5.1.3.35 | metabolism |
the enzyme is involved in the acarbose biosynthesis, pathway overview. The biosynthesis of the C7-cyclitol, called valienol (or valienamine), of the alpha-glucosidase inhibitor acarbose starts from the cyclization of sedo-heptulose 7-phosphate to 2-epi-5-epivaliolone. Synthesis of the intermediate 2-epi-5-epi-valiolone is catalyzed by the cyclase AcbC encoded in the biosynthetic (acb) gene cluster of Actinoplanes sp. SE50/110. The cyclitol precursor 2-epi-5-epi-valiolone is phosphorylated, forming the intermediate 2-epi-5-epi-valiolone 7-phosphate, by the enzyme AcbM as a first step in its conversion to the valienol moiety. Epimerase AcbO catalyzes the next conversion step, leading to an isomeric phosphorylated substance with the same molecular mass, most likely the epimerization product of 2-epi-5-epivaliolone 7-phosphate to 5-epi-valiolone 7-phosphate |
729959 |
