Crystallization and preliminary X-ray analysis of tyrosine aminotransferase from Trypanosoma cruzi epimastigotes

Tyrosine aminotransferase from Trypanosoma cruzi has been crystallized from PEG 4000 at pH 6.8. The crystals belong to the monoclinic space group P2₁ and have lattice constants of a = 59.1, b = 103.0, c = 77.8 Å, β = 113.1° for a data set measured at 138 K. The presence of a non-crystallographic twofold axis together with a Matthews parameter V_m of 2.5 ų Da⁻¹ indicates that the asymmetric unit contains one dimeric molecule. The crystals diffract to at least 2.7 Å and are stable in the X-ray beam in a shock-frozen state. Native data sets have been collected at temperatures of 285 and 138 K using a Siemens X1000 detector on a rotating-anode generator.