Overexpression, purification and crystallization of lysine epsilon-aminotransferase (Rv3290c) from Mycobacterium tuberculosis H37Rv.

Lysine epsilon-aminotransferase (LAT) is a protein involved in lysine catabolism; it belongs to the aminotransferase family of enzymes, which use pyridoxal 5'-phosphate (PLP) as a cofactor. LAT probably plays a significant role during the persistent/latent phase of Mycobacterium tuberculosis, as observed by its up-regulation by approximately 40-fold during this stage. Crystals of recombinant LAT have been grown in 0.1 M trisodium citrate dihydrate solution containing 0.2 M ammonium acetate and 25% PEG 4000 in the pH range 5.4-6.0. Diffraction data extending to 1.98 A were collected at room temperature from a single crystal. Crystals are trigonal in shape and belong to space group P3(1)21, with unit-cell parameters a = 103.26, b = 103.26, c = 98.22 A. The crystals contain a monomer in the asymmetric unit, which corresponds to a Matthews coefficient (V(M)) of 3.1 A3 Da(-1).