advertisement: compare things at compare-stuff.com!

CATH codes and domain identifiers

In the CATH database, each class, architecture, topology and homologous superfamily can be described by numbers of the form:

Class

3 (mixed-$\alpha \beta$)

Architecture

3.20 (mixed-$\alpha \beta$, barrel)

Topology

3.20.40 (mixed-$\alpha \beta$, barrel, TIM barrel)

Homologous superfamily

3.20.40.10 (1,3-$\beta$-glucanase superfamily)

Each domain in the database is identified by a six letter code of the form 1xyzA1, where `1xyz' is the PDB[Bernstein et al., 1977] identifier, `A' is the chain identifier, and `1' is the domain identifier. When no chain is specified in the PDB file, `0' is used. A `0' domain implies that the protein chain in question has a single domain.