The CATH Database provides insights into protein structure/function relationships.

af Orengo, C A, Pearl, F M, Bray, J E, Todd, A E, Martin, A C, Lo Conte, L, Thornton, J M
Udgivet 1999

The CATH database: an extended protein family resource for structural and functional genomics

af Pearl, F. M. G., Bennett, C. F., Bray, J. E., Harrison, A. P., Martin, N., Shepherd, A., Sillitoe, I., Thornton, J., Orengo, C. A.
Udgivet 2003