Purification, crystallization and preliminary X-ray crystallographic analysis of Lmo0540 from Listeria monocytogenes.

Penicillin-binding proteins catalyze the biosynthesis of the peptidoglycan chains of the bacterial cell wall, which protects cells from osmotic pressure. Although Lmo0540 has been identified as a putative penicillin-binding protein that contributes to the virulence of Listeria monocytogenes, the biochemical role of Lmo0540 remains unclear. To provide insights into its biochemical function, Lmo0540 was overexpressed, purified and crystallized by the sitting-drop vapour-diffusion method. Diffraction data were collected to 1.5 Å resolution using synchrotron radiation. The crystal belonged to the C-centred monoclinic space group C2, with unit-cell parameters a = 82.5, b = 75.7, c = 75.9 Å, α = γ = 90, β = 121.8°. A full structural determination is under way in order to elucidate the structure-function relationship of this protein.