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Updated: Aug 14, 2026
Crystallization and Structural Determination of an Enzyme:Substrate Complex by Serial Crystallography in a Versatile Microfluidic Chip
Published on: March 20, 2021
Intensity statistics in twinned crystals with examples from the PDB
Andrey A Lebedev1, Alexei A Vagin, Garib N Murshudov
1Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, England. lebedev@ysbl.york.ac.uk
Abstract:
Entries deposited in the Protein Data Bank as of February 2004 for which both model and X-ray data were available were analysed to identify cases of twinning using such simple statistics as the R factor between potential twin-related reflections. Careful consideration of all identified twins showed that in many cases twinning was ignored during structure solution and refinement. Manual analysis of the models showed that twinning often occurs in association with rotational pseudosymmetry parallel to the twinning operator. The coexistence of these two phenomena complicates the detection and diagnostics of twinning using currently available twinning tests. It was concluded that a twinning-detection step should be incorporated in every stage of structure analysis from data acquisition to refinement and validation.
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