Purification, crystallization and preliminary X-ray analysis of the lytic transglycosylase MltA from Escherichia coli

The lytic transglycosylase MltA from Escherichia coli with its membrane anchor and signal sequence deleted has been purified to homogeneity by means of cation-exchange chromatography. The enzyme was crystallized using the hanging-drop vapour-diffusion method. The crystals belong to space group P3₁21 or P3₂21, with unit-cell parameters a = b = 103.70, c = 109.84 Å and one molecule per asymmetric unit. Crystals diffract to 2.2 Å resolution on a synchrotron-radiation source.