Abstract
Valyl-tRNA synthetase [EC 6.1.1.9] from E. coli has been purified and crystallized. From still X-ray photographs, approximate cell dimensions have been obtained. The cell dimensions are a=125.0Å, b=154.0Å, and c=91.0Å with β near 90°, indicating an orthorhombic (monoclinic) unit cell. The rapid deterioration of the crystals in the X-ray beam made it impossible to determine the unit cell unequivocally. The crystalline material was proved to be valyl-tRNA synthetase by polyacrylamide gel electrophoresis.