Fold: Alpha-L RNA-binding motif

alpha(2)-beta(2)-loop-beta; 2 layers: alpha/beta

Lineage:

1. Root: scop
2. Class: Alpha and beta proteins (a+b)
   Mainly antiparallel beta sheets (segregated alpha and beta regions)
3. Fold: Alpha-L RNA-binding motif
   alpha(2)-beta(2)-loop-beta; 2 layers: alpha/beta

Superfamilies:

1. Alpha-L RNA-binding motif (3)
   common motif in otherwise different folds
   1. Threonyl-tRNA synthetase (ThrRS), N-terminal 'additional' domain (1)
      has a beta-grasp fold
   2. Ribosomal protein S4 (2)
      has a RRF/tRNA synthetase additional domain-like fold
   3. Heat shock protein 15 kD (1)
      there are additional C-terminal structures