PDB
From Structome.com
http://www.rcsb.org/pdb/The Protein Data Bank (PDB) is the single worldwide archive of structural data for biological macromolecules. The PDB is maintained by the Research Collaboratory for Structural Bioinformatics (RCSB). The Protein Data Bank (PDB) is the single international repository for public data on the 3-dimensional structures of biological macromolecules. The contents are primarily experimental data derived from X-ray crystallography and NMR experiments. The primary goals of this resource are:
The PDB database is available for complete download via ftp from ftp://ftp.rcsb.org/pub/pdb/data/structures/all/pdb/, and incremental updates are made possible using the rsync protocol (SERVER = rsync.rcsb.org, PORT = 33444).
