Panadda BoonsermDavid J. EllarJade LiUniversity of CambridgeThe Medical Research Council Laboratory of Molecular BiologyMahidol University2018-07-242018-07-242003-03-01Acta Crystallographica - Section D Biological Crystallography. Vol.59, No.3 (2003), 591-594090744492-s2.0-0037348708https://repository.li.mahidol.ac.th/handle/20.500.14594/20758The Cry4B δ-endotoxin from Bacillus thuringiensis subsp. israelensis is specifically toxic to mosquito larvae. For a better understanding of the mechanism of toxicity, chymotrypsin-activated Cry4B toxin (68 kDa) has been purified and crystallized in sodium bromide at neutral pH. The well formed crystals belong to the rhombohedral space group R32, with unit-cell parameters a = b = 185.82, c = 187.93 Å, and diffracted X-rays to 1.75 Å resolution. The asymmetric unit contains one toxin molecule and 74% solvent content, as shown by molecular replacement from a composite model of the homologous Cry3A and Cry1Aa. The purified protein and crystals both possessed mosquitocidal activity.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1107/S0907444903001513