Fold: HAD-like [56783]
3 layers: a/b/a; parallel beta-sheet of 6 strands, order 321456
Superfamily: HAD-like [56784]
usually contains an insertion (sub)domain after strand 1 uperfamily
Family: NagD-like [102317]
duplication: consists of two segment-swapped domains of this fold; this results in the insertion of a circularly permuted domain after strand 3, analogously to the Cof family