3DNF STRUCTURE OF (E)-4-HYDROXY-3-METHYL-BUT-2-ENYL DIPHOSPHATE REDUCTASE, THE TERMINAL ENZYME OF THE NON-MEVALONATE PATHWAY OXIDOREDUCTASE, TRILOBAL STRUCURE, OPEN ALPHA/BETA, 3FE-4S, IRON, IRON- SULFUR, ISOPRENE BIOSYNTHESIS, METAL-BINDING, NADP