What is CATH database?

CATH is a hierarchical domain classification of the three-dimensional (3D) structures of proteins deposited in the PDB and predicted structural annotations for protein domain sequences in UniProt. It is a free, publicly available online resource, developed in mid-1990s by Professors Christine Orengo and Janet Thornton at University College London (UCL), and co-workers; it continues to be developed by the Orengo group, at UCL.

The name CATH derives from the initials of the top four levels of the classification – (C)lass, (A)rchitecture, (T)opology and (H)omologous Superfamily. The CATH database is available at http://www.cathdb.info/ (Figure 1).

Explore what you can do with CATH database by clicking on the  below (Figure 1):

Figure 1 Homepage of CATH database.

To maintain accuracy when classifying and clustering protein domains, it is important to include high quality structures. For this reason, CATH processes only well-resolved 3D structures from PDB, by applying SIFT criteria. These criteria identify PDB entries with resolution ≤4 Å, resolved using X-ray crystallography/NMR, length criteria of > 40 residues and having >70% residues with non-α carbon atoms.