Just of the top of my head... PDB * Validation reports * Electron Density Maps * Others (listed in the PDBe API 'files' endpoint, e.g. http://www.ebi.ac.uk/pdbe/api/pdb/entry/files/1cbs) UniProt * Sequence annotations in other formats (http://www.uniprot.org/help/api_retrieve_entries) DSSP * Pre-computed DSSP from ftp://ftp.cmbi.ru.nl/pub/molbio/data/dssp (more info at http://swift.cmbi.ru.nl/gv/dssp/) Ensembl * Variants and other sequence annotations (more info at http://www.ensembl.org/info/data/ftp/index.html) CATH * Loads of additional data (more info at http://www.cathdb.info/download)
Just of the top of my head...
PDB
UniProt
DSSP
Ensembl
CATH