Experience with exchange and archiving of raw data: comparison of data from two diffractometers and four software packages on a series of lysozyme crystals.
The International Union of Crystallography has for many years been advocating
archiving of raw data to accompany structural papers. Recently, it initiated the
formation of the Diffraction Data Deposition Working Group with the aim of
developing standards for the representation of these data. A means of studying
this issue is to submit exemplar publications with associated raw data and
metadata. A recent study on the effects of dimethyl sulfoxide on the binding of
cisplatin and carboplatin to histidine in 11 different lysozyme crystals from
two diffractometers led to an investigation of the possible effects of the
equipment and X-ray diffraction data processing software on the calculated
occupancies and B factors of the bound Pt compounds. 35.3 Gb of data were
transferred from Manchester to Utrecht to be processed with EVAL. A systematic
comparison shows that the largest differences in the occupancies and B factors
of the bound Pt compounds are due to the software, but the equipment also has a
noticeable effect. A detailed description of and discussion on the availability
of metadata is given. By making these raw diffraction data sets available via a
local depository, it is possible for the diffraction community to make their own
evaluation as they may wish.
