Uroporphyrinogen-III synthase (HemD) catalyzes the asymmetrical cyclization of tetrapyrrole (linear) to uroporphyrinogen-III, the fourth step in the biosynthesis of heme. This ubiquitous enzyme is present in eukaryotes, bacteria and archaea. Mutations in the human uroporphyrinogen-III synthase gene cause congenital erythropoietic porphyria, a recessive inborn error of metabolism also known as Gunther disease.
Structure:3D8N; Thermus thermophilus Uroporphyrinogen III synthase with bound product uroporphyrinogen III, contacts defined at 4A. - View structure with Cn3D