The protein databases contain amino acid sequences derived from translations of the sequences stored in the nucleotide databases or resolved protein structures. The major protein sequence databases are GenPept (4), RefSeq (7), the Protein Information Resource (PIR) (8), the UniProt
Knowledgebase (UniProtKB) (9), which consists of the non-redundant, manually curated UniProtKB/Swiss-Prot and its computer-annotated supplement, UniProtKB/TrEMBL, which contains protein sequences translated from the EMBL nucleotide sequence database.