Fold: Histone-fold

core: 3 helices; long middle helix is flanked at each end with shorter ones

Lineage:

1. Root: scop
2. Class: All alpha proteins
3. Fold: Histone-fold
   core: 3 helices; long middle helix is flanked at each end with shorter ones

Superfamilies:

1. Histone-fold (3)
   1. Nucleosome core histones (10)
      form octamers composed of two copies of each of the four histones
   2. Archaeal histone (2)
   3. TBP-associated factors, TAFs (4)