Search the UniProt Archive (UniParc) for protein sequence entries. UniParc is a non-redundant archive that stores every publicly available protein sequence, combining sequences from multiple sources (UniProtKB, Ensembl, RefSeq, etc.). Each unique sequence gets a single UniParc identifier (UPI) regardless of which source database it came from. Use this endpoint to find sequences and their cross-references across multiple databases. Results include the sequence itself, cross-reference counts, common taxonomic information, and links to UniProtKB entries. This is useful for identifying all database entries that share the same protein sequence or for finding sequences by cross-reference.
Original spec description
Search the UniProt Archive (UniParc), a non-redundant archive of protein sequences from all sources.