February 2009 issue
Low-resolution structure determination and validation
Proceedings of the CCP4 study weekend
A case of imperfect pseudo-merohedral twinning in monoclinic crystals of fungal fatty acid synthase is discussed. A space-group transition during crystal dehydration resulted in a Moiré pattern-like interference of the twinned diffraction patterns.
X-ray crystallographic and complementary functional studies have contributed significantly to the current understanding of gene transcription. Here, recent structure–function studies on various aspects of the elongation phase of transcription are summarized.
Interpretation of low-resolution X-ray crystallographic data can prove to be a difficult task. The challenges faced in electron-density interpretation, the strategies that have been employed to overcome them and developments to automate the process are reviewed.
The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described.
In a first systematic exploration of phasing with Rosetta de novo models, it is shown that all-atom refinement of coarse-grained models significantly improves both the model quality and performance in molecular replacement with the Phaser software.
An evaluation of validation and real-space intervention possibilities for improving existing automated (re-)refinement methods.
An analysis is presented of the methodological errors that led to the incorrect structure of MsbA.