Expression, purification, crystallization and preliminary X‐ray crystallographic analysis of the L,D‐transpeptidase Ldt Mt1 from Mycobacterium tuberculosis

Mycobacterium tuberculosis is capable of adapting to prolonged periods of dormancy, a state which is resistant to killing by antimycobacterial agents. The L,D‐transpeptidation reaction catalysed by the L,D‐transpeptidase Ldt Mt1 is likely to play an essential role in the adaptation of M. tuberculosis to its dormant state. Ldt Mt1 has been successfully crystallized using vapour‐diffusion methods. The crystals of this protein belonged to space group P 6 5 22, with unit‐cell parameters a = 57.25, b = 57.25, c = 257.96 Å, α = 90, β = 90, γ = 120°. Diffraction data have also been collected from a selenomethionine derivative to 2.9 Å resolution. Model building using the phases derived from the multiwavelength anomalous dispersion experiment is in progress.