$$\sigma_{R}^{2}$$, a reciprocal-space measure of the quality of macromolecular electron-density maps

Journal Article · Tue Jun 01 00:00:00 EDT 1999 · Acta Crystallographica. Section D: Biological Crystallography

DOI:https://doi.org/10.1107/s0907444999003583· OSTI ID:1625687

Terwilliger, Thomas C. ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Structural Biology Group; DOE/OSTI

It has previously been shown that the presence of distinct regions of solvent and protein in macromolecular crystals leads to a high value of the standard deviation of local r.m.s. electron density and that this can in turn be used as a reliable measure of the quality of macromolecular electron-density maps [Terwilliger & Berendzen (1999a). Acta Cryst. D55, 501-505]. Here, it is demonstrated that a similar measure, $$\sigma_{R}^{2}$$, the variance of the local roughness of the electron density, can be calculated in reciprocal space. The formulation is suitable for rapid evaluation of macromolecular crystallographic phases, for phase improvement and for ab initio phasing procedures.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER). Biological Systems Science Division
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1625687
• Alternate ID(s): OSTI ID: 22347965
• Journal Information: Acta Crystallographica. Section D: Biological Crystallography, Journal Name: Acta Crystallographica. Section D: Biological Crystallography Journal Issue: 6 Vol. 55; ISSN 0907-4449
• Publisher: International Union of Crystallography
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
biochemistry & molecular biology
biophysics
crystallography
electron-density maps
phase quality
reciprocal space
roughness.