Nearly all proteins have structural similarities with other proteins and, in some of these cases, share a common evolutionary origin. The SCOP 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.
The Astral compendium provides databases and tools useful for analyzing protein structures and their sequences. It is partially derived from, and augments SCOP(e). Most of the resources provided here depend upon the coordinate files maintained and distributed by the Protein Data Bank.
Since 2004-07-01, all SCOP data have been freely available to all users, according to the license agreement. All ASTRAL data are also freely available to all users.