PDBeSIFTS Get PDB To Uniprot

Map PDB entry chains to UniProt protein accessions using PDBe SIFTS cross-referencing. For a given PDB structure, returns which UniProt proteins are present, which chains correspond to each protein, and the residue-level mapping between PDB and UniProt numbering. Essential for understanding multi-chain structures and identifying proteins in crystal/EM structures. Example: PDB 1tup maps chain A/B/C to P04637 (TP53) residues 94-312.