Fold: PRTase-like

core: 3 layers, a/b/a; mixed beta-sheet of 6 strands, order 321456; strand 3 is antiparallel to the rest

Lineage:

1. Root: scop
2. Class: Alpha and beta proteins (a/b)
   Mainly parallel beta sheets (beta-alpha-beta units)
3. Fold: PRTase-like
   core: 3 layers, a/b/a; mixed beta-sheet of 6 strands, order 321456; strand 3 is antiparallel to the rest

Superfamilies:

1. PRTase-like (2)
   1. Phosphoribosyltransferases (PRTases) (14)
   2. Phosphoribosylpyrophosphate synthetase (1)
      duplication: cosists of two domains of this fold