Direct Methods in Protein Electron Crystallography: the Ab Initio Structure Determination of Two Membrane Protein Structures in Projection using Maximum Entropy and Likelihood

Christopher J. Gilmore (Lead / Corresponding author), William V. Nicholson, Douglas L. Dorset

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Using maximum entropy and likelihood, an ab initio phase determination was carried out in projection at ca 6-10 Å resolution for two dissimilar membrane proteins: the Omp F porin from the outer membrane of E. coli (largely [beta]-sheet) and halorhodopsin (largely [alpha]-helix). Accurate phase information found for the most likely solutions enabled potential maps to be calculated that contained most of the essential structural details of these macromolecules without the need for any image, derived phases as a starting set for phase extension or the necessity to use envelopes or electron-density histograms. A comparison with earlier calculations using the Sayre-Hughes equation coupled with phase annealing and the Luzzati flatness criterion used as a figure of merit is made.
Original languageEnglish
Pages (from-to)937-946
Number of pages10
JournalActa Crystallographica Section A: Foundations and Advances
Volume52
Issue number6
DOIs
Publication statusPublished - 1 Nov 1996

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Halorhodopsins
Porins
Crystallography
Macromolecules
Escherichia coli
Carrier concentration
Membrane Proteins
Entropy
Annealing
Membranes
Electrons
Proteins

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abstract = "Using maximum entropy and likelihood, an ab initio phase determination was carried out in projection at ca 6-10 {\AA} resolution for two dissimilar membrane proteins: the Omp F porin from the outer membrane of E. coli (largely [beta]-sheet) and halorhodopsin (largely [alpha]-helix). Accurate phase information found for the most likely solutions enabled potential maps to be calculated that contained most of the essential structural details of these macromolecules without the need for any image, derived phases as a starting set for phase extension or the necessity to use envelopes or electron-density histograms. A comparison with earlier calculations using the Sayre-Hughes equation coupled with phase annealing and the Luzzati flatness criterion used as a figure of merit is made.",
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Direct Methods in Protein Electron Crystallography : the Ab Initio Structure Determination of Two Membrane Protein Structures in Projection using Maximum Entropy and Likelihood. / Gilmore, Christopher J. (Lead / Corresponding author); Nicholson, William V.; Dorset, Douglas L.

In: Acta Crystallographica Section A: Foundations and Advances, Vol. 52, No. 6, 01.11.1996, p. 937-946.

Research output: Contribution to journalArticle

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