How can I download the PDB in relational database format?
One possibility is to download all desired entries in mmCIF format from the PDB FTP site and then use • OpenMMS (see also this modified version which allows batch operation) or • Dbloader to create relational database tables. Supported DBMSs include MySQL and Oracle. Update: OpenMMS is no longer supported by the RCSB. You may however find some useful information in the OpenMMS mailing list archives. There is now a Biojava Hibernate Project which uses the Hibernate object-relational mapping framework to store Biojava structure objects in relational databases.