G. sulfurreducens and G. metallireducens possess different genes for molybdenum cofactor biosynthesis. (a) G. sulfurreducens has the global regulator modE. (b) G. metallireducens has multiple copies of moeA, moaA, and mosC, and putative integration host factor binding sites (black stripes). Both genomes have conserved genes (dark grey) for molybdate transport (modABC) and molybdopterin biosynthesis (moeA, moaCB, mobA-mobB, mosC) alongside tup genes for tungstate transport (white), but neither genome has all the genes thought to be essential for bis-(molybdopterin guanine dinucleotide)-molybdenum biosynthesis (light grey). See also Table 1.