Fold: DNA topoisomerase I domain

beta(2)-alpha-beta-(alpha)-beta(2); left-handed crossover between strands 2 & 3

Lineage:

1. Root: scop
2. Class: Alpha and beta proteins (a+b)
   Mainly antiparallel beta sheets (segregated alpha and beta regions)
3. Fold: DNA topoisomerase I domain
   beta(2)-alpha-beta-(alpha)-beta(2); left-handed crossover between strands 2 & 3

Superfamilies:

1. DNA topoisomerase I domain (1)
   1. Vaccinia DNA topoisomerase I, 9 kDa N-terminal fragment (1)
      1. Vaccinia DNA topoisomerase I, 9 kDa N-terminal fragment
         1. Vaccinia virus, strain WR (1)
            1. 1vcc