Open AccessDiffraction data analysis in the presence of radiation damage
Author(s) -
Borek Dominika,
Cymborowski Marcin,
Machius Mischa,
Minor Wladek,
Otwinowski Zbyszek
Publication year - 2010
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444909040177
Subject(s) - diffraction , phaser , x ray crystallography , radiation , limiting , scaling , crystal (programming language) , neutron diffraction , lattice (music) , radiation damage , crystallography , chemistry , materials science , chemical physics , computational physics , optics , physics , computer science , mathematics , mechanical engineering , geometry , acoustics , programming language , engineering
In macromolecular crystallography, the acquisition of a complete set of diffraction intensities typically involves a high cumulative dose of X‐ray radiation. In the process of data acquisition, the irradiated crystal lattice undergoes a broad range of chemical and physical changes. These result in the gradual decay of diffraction intensities, accompanied by changes in the macroscopic organization of crystal lattice order and by localized changes in electron density that, owing to complex radiation chemistry, are specific for a particular macromolecule. The decay of diffraction intensities is a well defined physical process that is fully correctable during scaling and merging analysis and therefore, while limiting the amount of diffraction, it has no other impact on phasing procedures. Specific chemical changes, which are variable even between different crystal forms of the same macromolecule, are more difficult to predict, describe and correct in data. Appearing during the process of data collection, they result in gradual changes in structure factors and therefore have profound consequences in phasing procedures. Examples of various combinations of radiation‐induced changes are presented and various considerations pertinent to the determination of the best strategies for handling diffraction data analysis in representative situations are discussed.