For proteins, the default database (nr) is a nonredundant set of all coding sequence translations translations from GenBank along with all RefSeq, Swiss-Prot, Protein Data Bank (PDB), Protein Information Resource (PIR) and Protein Research Foundation (PRF) proteins. Subsets of this database are also available, such as PDB or Swiss-Prot sequences, along with separate databases for sequences from patents and environmental samples. Like the nucleotide databases, these collections can be limited by taxonomy or an arbitrary Entrez query.
