2VPZ OXIDOREDUCTASE, MOLYBDOPTERIN GUANINE DINUCLEOTIDE, IRON-SULFUR, METAL-BINDING, MOLYBDOPTERIN, INTEGRAL MEMBRANE PROTEIN, MGD, MPT, IRON, FE4S4, 4FE-4S, MOLYBDENUM, IRON SULFUR CLUSTER POLYSULFIDE REDUCTASE NATIVE STRUCTURE