The Protein Data Bank

The Protein Data Bank (PDB) at Brookhaven National Laboratory, is a database containing experimentally determined three-dimensional structures of proteins, nucleic acids and other biological macromolecules. These data are released into the public domain and can be accessed for free. PDB files include the coordinates of every atom identified when the structure was solved.

References

Protein Data Bank (PDB): database of three-dimensional structural information of biological macromolecules.
Sussman JL, Lin D, Jiang J, Manning NO, Prilusky J, Ritter O, Abola EE
Acta Crystallogr D Biol Crystallogr54p1078-84(1998 Nov 1)