Abstract
The Protein Data Bank (PDB) is an archive of experimentally determined three-dimensional structures of proteins, nucleic acids, and other biological macromolecules with a 25 year history of service to a global community. PDB is being replaced by 3DB, the Three-Dimensional Database of Biomolecular Structures that will continue to operate from Brookhaven National Laboratory. 3DB will be a highly sophisticated knowledge-based system for archiving and accessing structural information that combines the advantages of object oriented and relational database systems. 3DB will operate as a direct-deposition archive that will also accept third-party supplied annotations. Conversion of PDB to 3DB will be evolutionary, providing a high degree of compatibility with existing software.