The Protein Data Bank (PDB) is a worldwide archive of 3D structural data of biological macromolecules including proteins and nucleic acids. It was established in 1971 and originally contained 7 structures. In 1998, the Research Collaboratory for Structural Bioinformatics took over management. In 2003, the worldwide PDB (wwPDB) was formed to maintain a single publicly available archive. The wwPDB consists of several partner organizations that act as deposition, processing, and distribution centers.