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Title: Improved Statistics for Determining the Patterson Symmetry fromUnmerged Diffraction Intensities

Abstract

We examine procedures for detecting the point-group symmetryof macromolecular datasets and propose enhancements. To validate apoint-group, it is sufficient to compare pairs of Bragg reflections thatare related by each of the group's component symmetry operators.Correlation is commonly expressed in the form of a single statisticalquantity (such as Rmerge) that incorporates information from all of theobserved reflections. However, the usual practice of weighting all pairsof symmetry-related intensities equally can obscure the fact that thevarious symmetry operators of the point-group contribute differingfractions of the total set. In some cases where particular symmetryelements are significantly under-represented, statistics calculatedglobally over all observations do not permit conclusions about thepoint-group and Patterson symmetry. The problem can be avoided byrepartitioning the data in a way that explicitly takes note of individualoperators. The new analysis methods, incorporated into the programLABELIT (cci.lbl.gov/labelit), can be performed early enough during dataacquisition, and are quick enough, that it is feasible to pause tooptimize the data collection strategy.

Authors:
; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE; National Institutes of Health. National Institute ofGeneral Medical Sciences Grant 1P50GM62412
OSTI Identifier:
881408
Report Number(s):
LBNL-58714
R&D Project: 864D6C
DOE Contract Number:
DE-AC02-05CH11231; NIH1P50GM62412
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Crystallography; Journal Volume: 39; Journal Issue: pt2; Related Information: Journal Publication Date: 04/2006
Country of Publication:
United States
Language:
English
Subject:
59; automation macromolecular LABELIT

Citation Formats

Sauter, Nicholas K., Grosse-Kunstleve, Ralf W., and Adams, Paul D. Improved Statistics for Determining the Patterson Symmetry fromUnmerged Diffraction Intensities. United States: N. p., 2006. Web.
Sauter, Nicholas K., Grosse-Kunstleve, Ralf W., & Adams, Paul D. Improved Statistics for Determining the Patterson Symmetry fromUnmerged Diffraction Intensities. United States.
Sauter, Nicholas K., Grosse-Kunstleve, Ralf W., and Adams, Paul D. Mon . "Improved Statistics for Determining the Patterson Symmetry fromUnmerged Diffraction Intensities". United States. doi:. https://www.osti.gov/servlets/purl/881408.
@article{osti_881408,
title = {Improved Statistics for Determining the Patterson Symmetry fromUnmerged Diffraction Intensities},
author = {Sauter, Nicholas K. and Grosse-Kunstleve, Ralf W. and Adams, Paul D.},
abstractNote = {We examine procedures for detecting the point-group symmetryof macromolecular datasets and propose enhancements. To validate apoint-group, it is sufficient to compare pairs of Bragg reflections thatare related by each of the group's component symmetry operators.Correlation is commonly expressed in the form of a single statisticalquantity (such as Rmerge) that incorporates information from all of theobserved reflections. However, the usual practice of weighting all pairsof symmetry-related intensities equally can obscure the fact that thevarious symmetry operators of the point-group contribute differingfractions of the total set. In some cases where particular symmetryelements are significantly under-represented, statistics calculatedglobally over all observations do not permit conclusions about thepoint-group and Patterson symmetry. The problem can be avoided byrepartitioning the data in a way that explicitly takes note of individualoperators. The new analysis methods, incorporated into the programLABELIT (cci.lbl.gov/labelit), can be performed early enough during dataacquisition, and are quick enough, that it is feasible to pause tooptimize the data collection strategy.},
doi = {},
journal = {Journal of Applied Crystallography},
number = pt2,
volume = 39,
place = {United States},
year = {Mon Jan 09 00:00:00 EST 2006},
month = {Mon Jan 09 00:00:00 EST 2006}
}