The Protein Data Bank is the international repository for biomacromolecular structures. Link to the home page, do a text search of PDB entries, check the status of unreleased entries, or deposit coordinates.

Pfam is a database of semi-automatic alignments of protein domains or conserved protein regions. Link directly to the home page, protein or DNA search pages, or browse Pfam alignments.

The ProDom database contains an automatic compilation of homologous protein domains. You can BLAST your sequence against the ProDom database.

The MultiCoil program predicts the location of coiled-coil regions in amino acid sequences and classifies whether the coils are likely to be dimeric or trimeric.

The DALI server searches the PDB for structural homologs of a protein. Go to the FSSP database to view structural neighbours of proteins already in the PDB.

The PredictProtein server finds homologs of a protein sequence, detects functional motifs and domains, and predicts secondary structure based on a single sequence or multiple sequence alignment.

The USA National Center for Biotechnology Information. You can go directly to the NCBI home page, PubMed database, genomes page, BLAST page, or specific BLAST of microbial and human genomes.

Expert Protein Analysis System server of the Swiss Institute of Bioinformatics. Go directly to the home page, the SWISS-PROT/TrEMBL text search, the PROSITE database of protein domains, submit a protein sequence to SWISS-PROT, or calculate the MW/pI of a protein.