4-∅ projection map of bacteriophage T4 DNA helix-destabilizing protein (gp32*I) crystal by 400-kV electron cryomicroscopy

T. Soejima, Michael Sherman, M. F. Schmid, W. Chiu

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Ice-embedded crystals of bacteriophage T4 DNA helix-destabilizing protein gp32*I were imaged by computer-controlled spot-scanning on a 400-kV electron cryomicroscope. gp32*I crystals generally have different steps of thickness within a crystal; each step can have different symmetry. Multivariate statistical analysis enabled us to unambiguously select spot-scan images that consist entirely of one motif which were porcessed subsequently by crystallographic Fourier-averaging techniques. The computed phases of the resulting reflections were evaluated for symmetry in projection, and some of those images were correlated with independent thickness measurements of freeze-dried samples of the same crystals. The structure factors with pgg symmetry from nine spot-scan images were merged, and the mean figure of merit of merged phases was better than 0.9 for data at resolution up to 4 ∅. A projection map was generated and showed multiple density peaks that corresponded to the high-resolution features of gp32*I.

Original languageEnglish (US)
Pages (from-to)9-16
Number of pages8
JournalJournal of Structural Biology
Volume111
Issue number1
DOIs
StatePublished - 1993
Externally publishedYes

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Cryoelectron Microscopy
DNA-Binding Proteins
Ice
Multivariate Analysis
Electrons
Enterobacteria phage T4 gp32 protein

ASJC Scopus subject areas

  • Structural Biology

Cite this

4-∅ projection map of bacteriophage T4 DNA helix-destabilizing protein (gp32*I) crystal by 400-kV electron cryomicroscopy. / Soejima, T.; Sherman, Michael; Schmid, M. F.; Chiu, W.

In: Journal of Structural Biology, Vol. 111, No. 1, 1993, p. 9-16.

Research output: Contribution to journalArticle

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