EXPRESSION OF RECOMBINANT NAD- INDEPENDENT FDH1 ALPHA SUBUNIT FROM METHYLOBACTERIUM EXTORQUENS AM1 IN ESCHERICHIA COLI AND REVERSIBLE INTERCONVERSION OF CARBON DIOXIDE AND FORMATE

摘要

Recent studies have revealed that NAD-dependent formate dehydrogenase(FDH1)isolated from the a-proteobacterium Methylobacterium extorquens AM1 showed extraordinary stability under aerobic conditions.The enzyme was found to be a heterodimer of two subunits(α1β1)of 107 and 61 kDa,respectively.Theα- subunit harbors binding motifs for the molybdopterin cofactor and at least one iron-sulfur cluster.Sequence identity was highest to the catalytic subunits of the tungsten and selenocysteine containing formate dehydrogenases characterized from Eubacterium acidaminophilum and Moorella thermoacetica(Clostridium thermoaceticum).