Crystallization and preliminary crystallographic study of the functional form of the Bacillus thuringiensis mosquito-larvicidal Cry4Aa mutant toxin.

The 65 kDa functional form of the mosquito-larvicidal Cry4Aa-R235Q mutant toxin has been crystallized. The crystals belong to space group C222(1), with unit-cell parameters a = 91.2, b = 202.1, c = 98.7 A, and contain one molecule per asymmetric unit. The crystals diffract to approximately 2.9 A using synchrotron radiation and a complete native data set has been collected. The structure has been solved using a molecular-replacement method with the Cry4Ba toxin protein as a search model.