Fig. 1.

This figure shows the smallest (left figure) and largest (middle figure) domain structures from the “Nitrogenase molybdenum iron protein domain” CATH superfamily (ID: 3.40.50.1980) and a superposition of all non-redundant structural relatives from that superfamily (non-redundant at 35% sequence identity) (right figure). The superposition shows that structural ‘core’ of related protein structures can remain highly conserved even after the amino acid sequence has changed beyond recognition.