W0105

Temporal and Global Features of Protein Structure Data. Helge Weissig and Philip E. Bourne, San Diego Supercomputer Center, University of California, San Diego, 9500 Gilman Drive, La Jolla CA, 92093 USA

All protein structures determined by X-ray crystallography and previously or currently held in the Protein Data Bank (PDB) have been analyzed. Where multiple versions of a structure exist, the change in stereochemical quality and general features of the obsolete versions are compared to the current version found in the PDB distribution. In some instances these changes are correlated with the year of deposition (temporal feature) and in others point to characteristics of the PDB as a whole (global feature). It is concluded that while stereochemistry has improved over time there is inconsistent reporting of structure and experimental detail. To a user of macromolecular structure data this study, like others before it, suggest that more attention, beyond the standard quality measures of resolution and R factor, should be considered when using coordinate sets for further derivation or in inferring biological function. To the crystallographic community this study suggests the need for more detailed and consistent reporting of structure data and the availability of that data in machine-readable form. Under such circumstances existing data could better influence how new experimental data are collected and atomic models determined, refined, and reported. Data for obsolete structures used in this study are available from the PDBObs database, http://pdbobs.sdsc.edu.