| Popis: |
A large group of molybdo- and tungstoenzymes utilizes “molybdopterin,” a hydrogenated pterin component, in the molybdenum cofactor (Moco) (1). Recent X-ray crystal structures of metal-molybdopterin enzymes have revealed at least three different structural types for Moco (2). Common to all of the crystal structures, however, is the coordination of the metal center by sulfur donors from the dithiolene groups of one or two molybdopterins. Additionally, the data show that the pterin portion is present in a previously unreported tricyclic form including a pyrano ring. |
