σ{sup 2}{sub R}, a reciprocal-space measure of the quality of macromolecular electron-density maps
- Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
A reciprocal-space measure of the quality of macromolecular crystallographic phases based on the variance of the local roughness of the map is presented. 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, θ{sub R}{sup 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.
- OSTI ID:
- 22347965
- Journal Information:
- Acta Crystallographica. Section D: Biological Crystallography, Vol. 55, Issue Pt 6; Other Information: PMCID: PMC2745888; PMID: 10329780; PUBLISHER-ID: gr0907; OAI: oai:pubmedcentral.nih.gov:2745888; Copyright (c) Terwilliger 1999; This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0907-4449
- Country of Publication:
- Denmark
- Language:
- English
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