Members of this family adopt a alpha-beta structure, with a core comprising three alpha/beta/alpha layers, in which each sheet contains four strands. They are predominantly found in prokaryotic methylene-tetrahydromethanopterin dehydrogenase, which catalyzes the dehydrogenation of methylene-tetrahydromethanopterin and the reversible dehydrogenation of methylene-H(4)F.
Jiyao W et al.(2023). "The conserved domain database in 2023.",