Figure 6. Groups of Fsr-N homologs.

The sketches are based on respective amino acid sequence characteristics shown in Fig. S4. FGltS(I)-α and aFsr-β: F₄₂₀H₂-dehydrogenase subunit of a putative F₄₂₀H₂-dependent glutamate synthase of methanogens and a putative F₄₂₀H₂-dependent assimilatory type siroheme sulfite reductase found in haloarchaea; FpoF/FqoF: F₄₂₀H₂ dehydrogenase subunit of a membrane-bound proton pumping F₄₂₀H₂ dehydrogenase complex of late evolving euryarchaea [36]. Note: FGltS(II)-α departs significantly from Fsr-N in primary sequence and it is not included in Fig. S4. F₄₂₀-interacting or β subunits of F₄₂₀H₂ reducing hydrogenase (FrhB) and formate dehydrogenase (FdhB) [67], [68] are shown for comparison.