In
enzymology,
SEPHCHC synthase (
EC ), encoded by menD gene in
E. coli, is an enzyme that catalyzes the second step of
menaquinone (vitamin K2) biosynthesis. The two substrates of this enzyme are
2-oxoglutarate and isochorismate. The products of this enzyme are 5-enolpyruvoyl-6-hydroxy-2-succinyl-cyclohex-3-ene-1-carboxylate and CO
2. It belongs to the transferase family.