UniProt

EMBL-EBI and SIB together used to produce Swiss-Prot and TrEMBL, while PIR produced the Protein Sequence Database (PIR-PSD). These two data sets coexisted with different protein sequence coverage and annotation priorities. TrEMBL (Translated EMBL Nucleotide Sequence Data Library) was originally created because sequence data was being generated at a pace that exceeded Swiss-Prot's ability to keep up. Meanwhile, PIR maintained the PIR-PSD and related databases, including iProClass, a database of protein sequences and curated families. In 2002 the three institutes decided to pool their resources and expertise and formed the UniProt consortium.

• Swiss-Prot, which is manually annotated and reviewed.

• TrEMBL, which is automatically annotated and is not reviewed.