Modelling and refining site-specific radiation damage in SAD/MAD phasing.
J Synchrotron Radiat
; 14(Pt 1): 34-42, 2007 Jan.
Article
in En
| MEDLINE
| ID: mdl-17211070
ABSTRACT
Site-specific radiation damage on anomalously scattering sites can be used to generate additional phase information in standard single- or multi-wavelength anomalous diffraction (SAD or MAD) experiments. In this approach the data are kept unmerged, down to the Harker construction, and the evolution of site-specific radiation damage as a function of X-ray irradiation is explicitly modelled and refined in real space. Phasing power is generated through the intensity differences of symmetry-related reflections or repeated measurements of the same reflection recorded at different X-ray doses. In the present communication the fundamentals of this approach are reviewed and different models for the description of site-specific radiation damage are presented. It is shown that, in more difficult situations, overall radiation damage may unfold on a time scale that is similar to the evolution of site-specific radiation damage or to the total time that is required to record a complete data set. In such cases the quality of the phases will ultimately be limited by the effects of overall radiation damage.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Models, Molecular
/
Crystallography, X-Ray
/
Macromolecular Substances
/
Models, Chemical
Language:
En
Journal:
J Synchrotron Radiat
Journal subject:
RADIOLOGIA
Year:
2007
Type:
Article
Affiliation country:
Switzerland