Expression, crystallization and preliminary X-ray diffraction studies of recombinant Bacillus anthracis lethal factor

The lethal factor (LF) produced by Bacillus anthracis is a Zn²⁺-dependent endopeptidase which specifically cleaves the N-terminal tail of several MAP kinase kinases (MAPKKs). The recombinant expression, purification and crystallization of LF and of an inactive mutant consisting of a single amino-acid substitution in the conserved catalytic site are reported here. Both proteins crystallize in the cubic space group I432.