Figure 4.

Predicted functional systems and general metabolic pathways of M. kandleri compared with the counterparts in other archaeal methanogens. Specific enzymatic reactions predicted in a given species but not in the other two are color-coded blue (M. kandleri), green (M. thermoautotrophicus), and red (M. jannaschii). Gene identifiers are shown only for M. kandleri. The methanogenesis pathway is shown by magenta arrows. Reactions for which no candidate enzyme was confidently predicted are shown by dashed arrows. Final biosynthetic products are shown as follows: light blue for amino acids, dark yellow for nucleotides, brown for sugars, pink for cofactors. MF, methanofuran; FMF, formyl-methanofuran; H4MPT, tetrahydromethanopterin; CoM, coenzyme M.