Fold: BRCT domain

3 layers, a/b/a; core: parallel beta-sheet of 4 strands, order 2134

Lineage:

1. Root: scop
2. Class: Alpha and beta proteins (a/b)
   Mainly parallel beta sheets (beta-alpha-beta units)
3. Fold: BRCT domain
   3 layers, a/b/a; core: parallel beta-sheet of 4 strands, order 2134

Superfamilies:

1. BRCT domain (2)
   1. DNA-repair protein XRCC1 (1)
   2. NAD+-dependent DNA ligase, domain 4 (1)