7,8-dihydromethanopterin + AH2 => 5,6,7,8-tetrahydromethanopterin + A
7,8-dihydromethanopterin + ah2 => 5,6,7,8-tetrahydromethanopterin + a
7,8-dihydromethanopterin + AH2 => 5,6,7,8-tetrahydromethanopterin + A
7,8-dihydromethanopterin + ah2 => 5,6,7,8-tetrahydromethanopterin + a