Fold: ATP-grasp

Consists of two subdomains with different alpha+beta folds
shares functional and structural similarities with the PIPK and protein kinase superfamilies

Lineage:

1. Root: scop
2. Class: Alpha and beta proteins (a+b)
   Mainly antiparallel beta sheets (segregated alpha and beta regions)
3. Fold: ATP-grasp
   Consists of two subdomains with different alpha+beta folds
   shares functional and structural similarities with the PIPK and protein kinase superfamilies

Superfamilies:

1. Glutathione synthetase ATP-binding domain-like (6)
2. DNA ligase/mRNA capping enzyme, catalytic domain (3)
   has a circularly permuted topology