CHARACTERIZATION OF THE CDHD AND CDHE GENES ENCODING SUBUNITS OF THE CORRINOID/IRON-SULFUR ENZYME OF THE CO DEHYDROGENASE COMPLEX FROM METHANOSARCINA THERMOPHILA

摘要: The CO dehydrogenase enzyme complex from Methanosarcina thermophila contains a corrinoid/iron-sulfur composed of two subunits (delta and gamma). cdhD cdhE genes, which encode the delta gamma subunits, respectively, were cloned sequenced. gene is upstream separated by 3 bp cdhE. Both genes are preceded apparent ribosome-binding sites. Northern (RNA) blot primer extension analyses indicated that cotranscribed promoter located several kilobases cdhD. putative CdhD CdhE sequences 37% identical to deduced encoding beta alpha Clostridium thermoaceticum. sequence had four-cysteine motif with potential bind 4Fe-4S cluster previously identified in electron paramagnetic resonance spectroscopy. A T7 RNA polymerase/promoter system was used produce independently Escherichia coli. purified protein reconstituted hydroxocobalamin base-on configuration. exhibited an Fe-S center base-off cobalamin binding benzimidazole base nitrogen atom no longer lower axial ligand cobalt atom.