Crystallization and preliminary X-ray diffraction analysis of the tRNA-modification enzyme GidA from Aquifex aeolicus

The 5-carboxymethylaminomethyl modification of uridine at the first position of the tRNA anticodon is crucial for accurate protein synthesis by stabilizing the correct codon–anticodon pairing on the ribosome. Two conserved enzymes, GidA and MnmE, are involved in this modification process. Aquifex aeolicus GidA was crystallized in two different crystal forms: forms I and II. These crystals diffracted to 3.2 and 2.3 Å resolution, respectively, using synchrotron radiation at the Photon Factory. These crystals belonged to space groups I2₁2₁2₁ and P2₁ with unit-cell parameters a = 101.6, b = 213.3, c = 231.7 Å and a = 119.4, b = 98.0, c = 129.6 Å, β = 90.002°, respectively. The asymmetric units of these crystals are expected to contain two and four molecules, respectively.