Properties of the tungsten-substituted molybdenum formylmethanofuran dehydrogenase from Methanobacterium wolfei

AbstractIn Methanobacterium wolfei two formylmethanofuran dehydrogenases are present, one of which is a molybdenum- and the other a tungsten enzyme. We report here that also the ‘molybdenum’ enzyme contained tungsten when the archaeon was grown on molybdenum-deprived medium supplemented with tungstate (1 μM). Unexpectedly the tungsten-substituted molybdenum enzyme was catalytically active and displayed a rhombic EPR signal which was attributed to tungsten by the characteristic 113W splitting