Figure 4.

Organization of genes encoding putative membrane-bound multiprotein complexes in T. aggregans and related members of Desulfurococcaceae. Operons of reference genes with asserted function are shown in the first line of each group. Genes with an assumed homologous function are labeled in the same color. Genes encoding subunits of putative multimeric cation-proton antiporters are shown in shades of green; genes with similarity to subunits of [NiFe] hydrogenases/NADH-quinone oxidoreductases are shown in red colors; genes representing the large and small subunit of supposed formate dehydrogenases are displayed in dark and light blue, respectively; genes labeled in yellow are homologous to genes encoding the alpha-subunit of Pyrococcus furiosus sulfide dehydrogenase (sudA); and genes representing hypothetical proteins of unknown function are shown in white. A) MBH-related energy-coupling hydrogenases. B) MBX-related ferredoxin-NADPH oxidoreductases. C) MBX-related ferredoxin-NADPH oxidoreductases. The reference operon of Thermococcus litoralis has been retrieved by cloning a fragment of genomic DNA, so that the arrangement of genes following mnhF could not be determined.