Nearly all proteins have structural similarities with other proteins and, in some of these cases, share a common evolutionary origin.
database, created by manual inspection and abetted by a battery of automated methods, aims to provide a detailed and
comprehensive description of the structural and evolutionary relationships between all proteins whose structure is known. As such,
it provides a broad survey of all known protein folds, detailed information about the close relatives of any particular protein, and a
framework for future research and classification.
Here you can browse by SCOP structural classifications (version 1.75