Related Experiment Video
Updated: Aug 29, 2026

Modeling an Enzyme Active Site using Molecular Visualization Freeware
Published on: December 25, 2021
The Catalytic Site Atlas: a resource of catalytic sites and residues identified in enzymes using structural data
Craig T Porter1, Gail J Bartlett, Janet M Thornton
1EMBL-EBI, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK.
Abstract:
The Catalytic Site Atlas (CSA) provides catalytic residue annotation for enzymes in the Protein Data Bank. It is available online at http://www.ebi.ac.uk/thornton-srv/databases/CSA. The database consists of two types of annotated site: an original hand-annotated set containing information extracted from the primary literature, using defined criteria to assign catalytic residues, and an additional homologous set, containing annotations inferred by PSI-BLAST and sequence alignment to one of the original set. The CSA can be queried via Swiss-Prot identifier and EC number, as well as by PDB code. CSA Version 1.0 contains 177 original hand- annotated entries and 2608 homologous entries, and covers approximately 30% of all EC numbers found in PDB. The CSA will be updated on a monthly basis to include homologous sites found in new PDBs, and new hand-annotated enzymes as and when their annotation is completed.
Related Concept Videos
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Ligand Binding and Linkage
Introduction to Mechanisms of Enzyme Catalysis
Enzymes
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Catalytically Perfect Enzymes
Turnover Number and Catalytic Efficiency
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion. The...

