Cloning, purification, crystallization and preliminary crystallographic analysis of Bacillus subtilis LuxS

LuxS of Bacillus subtilis is a member of a novel family of proteins with a potential role in quorum sensing, controlling important aspects of cellular physiology in a range of microbial species. B. subtilis luxS was cloned, e xpressed in Escherichia coli, purified and crystallized using the hanging-d rop method of vapour diffusion with ammonium sulfate as the precipitant. Th e crystals belong to one of the enantiomorphic space groups P6(1)22 or P6(5 )22, with approximate unit-cell parameters a = b = 63.6, c = 151.5 Angstrom and one subunit in the asymmetric unit, corresponding to a packing density of 2.5 Angstrom (3) Da(-1). The crystals diffract X-rays to at least 1.55 Angstrom resolution on a synchrotron-radiation source. Determination of the structure will provide insights into the key determinants of function of t his class of proteins, for which no structures are currently available.