Crystallization of a membrane pore‐forming protein with mosquitocidal activity from Bacillus thuringiensis subspecies kyushuensis

Jade Li, Pandelakis A. Koni, David J. Ellar

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4 Scopus citations


CytB, a membrane pore‐forming toxin from Bacillus thuringiensis subspecies kyushuensis, is specifically toxic to dipteran insect larvae but broadly cytolytic in vitro. It has been purified in the protoxin form from a recombinant Escherichia coli source and crystals have been obtained which diffract X‐rays to at least 2.6 Å resolution. The tendency for CytB to aggregate in solution was overcome by including 50 mM of urea or 8 mM of ethanolamine during crystallization. Mutants designed to add or subtract single cysteine residues for the purpose of heavy atom derivative preparation were similarly purified and crystallized. The crystals are hexagonal bipyramids. They belong to space group P6122 (or P6522) with lattice constants a = b = 67.34 Å, c = 170.96 Å, and contain one molecule of the CytB protoxin (MW 29235) per asymmetric unit and 27% solvent by volume. © 1995 Wiley‐Liss, Inc.

Original languageEnglish (US)
Pages (from-to)290-293
Number of pages4
JournalProteins: Structure, Function, and Bioinformatics
Issue number2
Publication statusPublished - Oct 1995



  • CytB
  • X‐ray diffraction
  • crystals
  • cytolytic
  • insecticide
  • purification

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology

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