Compiled by Craig Porter, Gail Bartlett, James Torrance, Nicholas Furnham and Janet Thornton.

European Bioinformatics Institute
Wellcome Trust Genome Campus
Hinxton, CB10 1SD, UK

The Catalytic Site Atlas (CSA) is a database documenting enzyme active sites and catalytic residues in enzymes of 3D structure. We defined a classification of catalytic residues which includes only those residues thought to be directly involved in some aspect of the reaction catalysed by an enzyme. For a full description of the classification, see Reference 2.

The CSA contains 2 types of entry:

1. Original hand-annotated entries, derived from the primary literature. References for these entries are given.
2. Homologous entries, found by PSI-BLAST alignment (using an e value cut-off of 0.00005) to one of the original entries. The equivalent residues, which align in sequence to the catalytic residues found in the original entry are documented.

Access to the CSA is via PDB code, SWISS-PROT entry or E.C. number. Accessing via PDB code takes you straight to the CSA entry for that PDB, while accessing via SWISS-PROT or E.C. number gives a list of all PDB codes for structures assigned that particular SWISS-PROT identifier or E.C. number. Structures with entries in the CSA are given as hyperlinks.

Each CSA entry lists the catalytic residues found in that entry, using PDB residue numbering. Each site is also marked with an evidence tag, which is either "Literature reference" or "PSI-BLAST hit". If the entry is a PSI-BLAST hit you can follow the link to the original entry. The active site can be visualised using RasMol, for detailed instructions on how to set this up, please click here.

Each entry contains a link to a list of homologous entries found by PSI-BLAST, and a link to other PDB structures with identical E.C. numbers or SWISS-PROT identifier to the entry you are viewing.

Thanks to everyone that contributed to the Catalytic Site Atlas:
Jonathan Barker, Carine Berezin, Lynn Carr, Olivia Chan, Josephine Charalambous, Emma Compton, Atlanta Cook, Jennifer Dawe, Christian Drew, Alex Gutteridge, Roman Laskowski, Mei Leung, Stuart Lucas, Malcolm MacArthur, Gary McDowell, Angela Malumbe, Duncan Milburn, Fiona Morgan, James Murray, Nozomi Nagano, Jonathan Ng, Emma Penn, Peter Sarkies, Steven Smith, Annabel Todd, Andrew Wallace, Anna Waters, and Eleanor Wright.

1. The Catalytic Site Atlas: a resource of catalytic sites and residues identified in enzymes using structural data. Craig T. Porter, Gail J. Bartlett, and Janet M. Thornton (2004) Nucl. Acids. Res. 32: D129-D133.
2. Analysis of Catalytic Residues in Enzyme Active Sites. Gail J. Bartlett, Craig T. Porter, Neera Borkakoti, and Janet M. Thornton (2002) J Mol Biol 324:105-121.
3. Using a Library of Structural Templates to Recognise Catalytic Sites and Explore their Evolution in Homologous Families. James W. Torrance, Gail J. Bartlett, Craig T. Porter, Janet M. Thornton (2005) J Mol Biol. 347:565-81