Diffraction data deposition

Abstract

A formal discussion of the archival journal requirements for data deposition was held at the International Seminar-cum-School on Macromolecular Crystallographic Data at Calcutta, India in November 1995.The current policy of the International Union of Crystallography (IUCr) is that on publication of a crystal structure determination of a macromolecule the atomic parameters used or represented in the publication must be deposited in the Brookhaven Protein Data Bank. The deposition of structure amplitudes is recommended but not obligatory. The policy provides crystallographers with the option to delay the release of atomic parameters for one year and of structure amplitudes for up to four years from the date of publication. Participants strongly supported this policy and felt it should be strictly applied by the journals.Recent developments in X-ray crystallographic experimental and refinement techniques and the huge expansion in computing power and networking, however, necessitate the review of deposition arrangements.It was noted that the new validation procedures are much more effective but require the experimental structure amplitudes as well as the atomic parameters. In addition, the technical arrangements for deposition, analysis and validation of macromolecular crystal structures are now much easier.We consider it vital for macromolecular crystallographers to respond to these developments in their deposition practices. We recommend, therefore, that publication of macromolecular crystal structures should be accompanied by deposition of atomic parameters and also structure amplitudes. Amongst the many reasons identified for this practice, the following two are critical.(1) Rigorous validation of the structure determination results can only be carried out using both atomic parameters and experimental structure amplitudes. It is important that journals ensure referees have sufficient information to prevent incorrect structures being published.(2) Archiving of these data will ensure that they are not lost. There were numerous reports at this meeting of data being lost. This probably reflects a widespread problem in the crystallographic community.