The files below incorporate the main information in the CSA in comma-separated value file format. You may wish to consult the original CSA paper (pubmed ID 14681376) in making sense of this data.
Each line in each file corresponds to a single catalytic residue.
The CSA includes entries directly annotated from the literature (literature entries), and other entries that are annotated by using PSI-BLAST to align them with the literature entries (PSI-BLAST entries). The comma-separated files include both literature and PSI-BLAST entries. The two are distinguished by the EVIDENCE TYPE field, which reads "LIT" for the literature entries. The LITERATURE ENTRY field states which literature-annotated entry is the parent of a given PSI-BLAST entry.
The individual residues are grouped together into catalytic sites. There can be multiple sites in a given PDB entry, particularly where there are multiple chains, or where different parent literature entries indicate different catalytic residues for a PSI-BLAST entry; these different sites are distinguished by different site numbers.
Note that there are cases where catalytic residues in a single site are spread over multiple chains. In relatives of the literature entry for which one of these chains is absent from the PDB structure, only the residues which are present will be listed. In relatives where both chains are present, but they are in a non-biological orientation relative to one another, all the residues are listed, but the contributions from each chain are treated as separated sites.
The CHEMICAL FUNCTION field contains details of which part of the residue is directly involved in catalysis: the sidechain (S), the backbone amide (N) or the backbone carbonyl (O). These may occur in combination.
