Protein expression, crystallization and preliminary X-ray crystallographic studies of LidA from Legionella pneumophila.

LidA, a translocated substrate of the Legionella pneumophila Dot/Icm type IV secretion system, is associated with maintenance of bacterial integrity and interferes with the early secretory pathway. However, the precise mechanism of LidA in these processes remains elusive. To further investigate the structure and function of LidA, the full-length protein was successfully expressed in Escherichia coli and purified. LidA was crystallized using sitting-drop vapour diffusion and diffracted to a resolution of 2.75 Å. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 57.5, b = 64.5, c = 167.3 Å, α = β = γ = 90°. There is one molecule per asymmetric unit.