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An improved phase-extension procedure for isomorphous replacement phases.

Y Vekhter·R Miller
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Abstract

A new phase-extension procedure has been applied to isomorphous replacement data and shown to yield improved phases and maps compared with standard solvent flattening operating on a full set of centroid phases. In this procedure, a starting subset of core phases is selected based on the sharpness of the phase-probability curves. Phase extension using solvent flattening as the density-modification procedure is then carried out, gradually adding additional phases. In tests with known protein structures, the mean phase errors for the output expanded phase sets were reduced by 3-9 degrees and the corresponding map correlation coefficients were increased by 0.05-0.18 relative to phase sets from standard solvent-flattening procedures. With SIR data, the lowest final mean phase errors were approximately 58 degrees and the corresponding map correlation coefficients were in the range 0.53-0.68.

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Protein ConformationProteinsJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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BibTeXRIS

Y Vekhter, R Miller. 2001-06-21. An improved phase-extension procedure for isomorphous replacement phases.. https://doi.org/10.1107/s0907444901005881

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