5,6,7,8-tetrahydromethanopterin biosynthesis PMID:8639495 PMID:15262968 methanopterin biosynthesis UPa:UPA00065 Biosynthesis of 5,6,7,8-tetrahydromethanopterin (H4MPT), a cofactor in methanogenesis. H4MPT is the carrier of the C1 group as it is reduced to the methyl level, before transferring to the coenzyme M. H4MPT biosynthesis pathway cofactor biosynthesis