Stands for the Protein Data Bank. Conceived of in the late 70's in Cambridge by Bernstein and colleagues. This is a repository for structures of biological macromolecules (i.e. proteins and nucleic acids). Originally a printed list of atomic coordinates, it soon was distributed on magnetic tape. Now, due to the wonders of the internet, it is freely accessible by all at

http://www.rcsb.org/pdb

The PDB has grown from a handful of structures upon its conception to over 12,000 structures as of the writing of this node - summer 2000. It is increasing at a practically exponential rate as more and more labs successfully solve protein structures using X-ray crystallography and NMR techniques. This database is then useful to other labs trying to understand protein function on the basis of structure. People use these structures to model homologous proteins, hoping that they can get an approximate idea of the protein shape based on evolutionary relationships with proteins of known structure.