The use of high halide-ion concentrations and automated phasing procedures for the structural analysis of BclA, the major component of the exosporium of Bacillus anthracis spores.

The structure determination of the recombinant form of BclA, the major protein component of Bacillus anthracis exosporium, involved soaking in a high concentration of potassium iodide as the means of obtaining a good-quality heavy-atom derivative. The data to 2 angstroms resolution collected on a laboratory source were of sufficient quality to allow successful phasing and chain tracing by automated methods.