PMID: 16131760 , Related PDB ids: 2A7A, 2A7B, 2A7C, 2A7D, 2A7E, 2A7F, 2A7G, 2A7H, 2A7I, 2A7J, R2A7ASF, R2A7BSF, R2A7CSF, R2A7DSF, R2A7ESF, R2A7FSF, R2A7GSF, R2A7HSF, R2A7ISF, R2A7JSF

Authors:

Mueller-Dieckmann C, Panjikar S, Tucker PA, Weiss MS

Title:

On the routine use of soft X-rays in macromolecular crystallography. Part III. The optimal data-collection wavelength.

Journal:

Acta Crystallogr D Biol Crystallogr. 2005 Sep;61(Pt 9):1263-72. Epub 2005, Aug 16.

Abstract:

Complete and highly redundant data sets were collected at different wavelengths between 0.80 and 2.65 A for a total of ten different protein and DNA model systems. The magnitude of the anomalous signal-to-noise ratio as assessed by the quotient R(anom)/R(r.i.m.) was found to be influenced by the data-collection wavelength and the nature of the anomalously scattering substructure. By utilizing simple empirical correlations, for instance between the estimated deltaF/F and the expected R(anom) or the data-collection wavelength and the expected R(r.i.m.), the wavelength at which the highest anomalous signal-to-noise ratio can be expected could be estimated even before the experiment. Almost independent of the nature of the anomalously scattering substructure and provided that no elemental X-ray absorption edge is nearby, this optimal wavelength is 2.1 A.