[1] All possess a similar structure, with a beta-alpha-beta fold characteristic of nucleotide binding proteins.

[2] The fold comprises a parallel beta-8/alpha-8-barrel, which contains a novel NADP-binding motif.

The binding site is located in a large, deep, elliptical pocket in the C-terminal end of the beta sheet, the substrate being bound in an extended conformation.

The hydrophobic nature of the pocket favours aromatic and apolar substrates over highly polar ones.

[4] Some proteins of this family contain a potassium channel beta chain regulatory domain; these are reported to have oxidoreductase activity.