The One-Carbon Carrier Tetrahydromethanopterin in Enzymes

The one-carbon (C₁) carrier tetrahydromethanopterin (H₄MPT), that non-covalently binds as cofactor to proteins, became more and more important in the last years, as it was discovered in several phylogenetically distinct microorganisms where it plays a pronounced role in the C₁ metabolism. Interestingly, its structure is highly similar to that of tetrahydrofolate (H₄F), the most universal C₁ carrier in biochemistry, but most likely H₄MPT and H₄F were separately developed within a convergent evolutionary process. The mode how H₄MPT binds to enzymes was recently established on a structural level for two systems that will be introduced.