Expression, purification, crystallization and preliminary X-ray crystallographic analysis of the L,D-transpeptidase LdtMt1 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 LdtMt1 is likely to play an essential role in the adaptation of M. tuberculosis to its dormant state. LdtMt1 has been successfully crystallized using vapour-diffusion methods. The crystals of this protein belonged to space group P6₅22, 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.