Table 2.

Structural novelty of MCSG structures.

Level of structural novelty	Number of domains (cumulative total)
Fold	54
Superfamily	66 (120)
Structural sub-group (SSG)	52 (172)

Number of novel CATH structural domains solved by the MCSG. Three levels of novelty are defined: a domain with a novel fold is the first example released by the PDB of a fold in CATH (a new CAT number); a domain belonging to a novel superfamily is the first example released by the PDB of a superfamily in CATH (a new CATH number); a domain belonging to a novel structural sub-group (SSG) has a normalized RMSD of at least 5Å from all previously existing domains in CATH.