Differential expression of genes annotated for fmd and fwd in M. acetivorans. Panel A) the six and five gene fmdE1F1A1C1D1B1 and fmdF2A2C2D2B2 clusters encoding the two putative molybdenum-type formylmethanofuran dehydrogenase enzyme complexes. Panel B) the four and three gene fwdD1B1A1C1 and fwdG2B2D2 clusters encoding the two putative tungsten-type formylmethanofuran dehydrogenase enzyme complexes. The Genebank identification number (MA number) is shown below each gene while the individual gene designation is shown above. Panel C) RT-PCR data for the indicated fmd and fwd genes. Values are expressed as copy number (Methods).