2A7A

On the Routine Use of Soft X-Rays in Macromolecular Crystallography, Part III- The Optimal Data Collection Wavelength

Summary for 2A7A

• Entry DOI: 10.2210/pdb2a7a/pdb
• Related: 1CNV
• Descriptor: Concanavalin A, MANGANESE (II) ION, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: lectin, metal binding protein
• Biological source: Canavalia virosa
• Total number of polymer chains: 1
• Total formula weight: 26373.87

Authors

Mueller-Dieckmann, C.,Panjikar, S.,Tucker, P.A.,Weiss, M.S. (deposition date: 2005-07-05, release date: 2005-07-19, Last modification date: 2024-02-14)

Primary citation

Mueller-Dieckmann, C.,Panjikar, S.,Tucker, P.A.,Weiss, M.S.
On the routine use of soft X-rays in macromolecular crystallography. Part III. The optimal data-collection wavelength.
Acta Crystallogr.,Sect.D, 61:1263-1272, 2005

PubMed 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.

PubMed: 16131760
DOI: 10.1107/S0907444905021475

Experimental method

X-RAY DIFFRACTION (1.75 Å)