Table 2. Data files available from the wwPDB and RCSB PDB ftp sites for download.

Resource	Description	URL
PDB Archive	PDB structure data, structure factor files, NMR restraint files, NMR chemical shift files, validation reports; Chemical Component Dictionary, BIRD dictionary	ftp://ftp.wwpdb.org/
		Data mirrors:
		ftp://ftp.ebi.ac.uk/pub/databases/pdb/
		ftp://ftp.pdbj.org/pub/pdb/
PDB Archive/EM	EM maps associated with EM structures in the PDB	ftp://ftp.wwpdb.org/pub/emdb/
Sequence Clusters	Grouped PDB protein sequences clustered from 30% to 100% sequence identity	ftp://resources.rcsb.org/sequence/clusters/
Structures determined by multiple methods	Clusters of structures determined by multiple methods (57)	ftp://resources.rcsb.org/sequence/clusters/