The Genome Sequence of Methanohalophilus mahii SLPT Reveals Differences in the Energy Metabolism among Members of the Methanosarcinaceae Inhabiting Freshwater and Saline Environments
Figure 6
Comparison of proposed energy conserving electron-transfer routes in (a) freshwater-inhabiting and (b) saltwater-adapted members of the family Methanosarcinaceae. The proposed models of the energy metabolism are mainly based on the results of gene deletion and expression analyses in the species Msc. barkeri [54], Msc. mazei [55] and Msc. acetivorans [42, 56, 57]. The postulated coupling ion for ATP-synthesis is shown in blue (H+) or red (Na+). Enzyme complexes and reactions that are thought to bypass the main route of electron transfer are shown in grey. The shown electron bifurcation at the HdrABC complex is based on a proposal of Buan and Metcalf [58]. A membrane-bound sodium-translocating Mtr complex that could participate in the utilization of a chemiosmotic gradient was omitted from the figure for simplicity reasons. Abbreviations for electron transfer complexes and cofactors are explained in the text and Table 3.
