Structural and functional features of the NAD(P) dependent Gfo/Idh/MocA protein family oxidoreductases

The Gfo/Idh/MocA protein family contains a number of different proteins, which almost exclusively consist of NAD(P)-dependent oxidoreductases that have a diverse set of substrates, typically pyranoses. In this study, to clarify common structural features that would contribute to their function, the available crystal structures of the members of this family have been analyzed. Despite a very low sequence identity, the central features of the three-dimensional structures of the proteins are surprisingly similar. The members of the protein family have a two-domain structure consisting of a N-terminal nucleotide-binding domain and a C-terminal α/β-domain. The C-terminal domain contributes to the substrate binding and catalysis, and contains a βα-motif with a central α-helix carrying common essential amino acid residues. The β-sheet of the α/β-domain contributes to the oligomerization in most of the proteins in the family.