CATH and Structural Classification of Proteins (SCOP) are structure classification databases in which proteins are parsed into domains. An individual domain structure can be retrieved by specifying its corresponding database identifier in the Fetch by ID dialog, or in the open command with cath: or scop: prepended. See also: Chimera input file types
A CATH domain identifier has 7 characters: the 4-character PDB ID + the PDB chain ID (where case is important) + a two-digit domain number (“00” for whole-chain domains). Examples: