From: SSMap: A new UniProt-PDB mapping resource for the curation of structural-related information in the UniProt/Swiss-Prot Knowledgebase
Data type\Mapping source
SSMap
DR PDB
SIFTS
PDBSWS
1. Number of mappings (AC, PDB chain)
91,050
78,238
84,398
93,167
2. Number of PDB chains mapped
90,923
77,711
93,141