Crystals of 70S ribosomes from thermophilic bacteria are suitable for X-ray amalysis at low resolution

Single crystals of 70S ribosomes from Thermus thermophilus and from the wild-type and a mutant of Bacillus stearothermophilus have been obtained. Using synchroton X-ray beam, these crystals diffract to 19 Å and 35 Å, respectively, and can be irradiated at temperatures of 110–120 K for days without noticeable decay. Diffraction data sets to 22 Å and to 33 Å with reasonable R scale were collected from the crystals of 70S from T. thermophilus. The cell dimensions (a = b = 524 Å, c = 315 Å), the symmetry $(P4_12_12 or P4_32_12)$ and the density (1.063 g/cm3) of these crystals indicate that there is one 70S ribosome per asymmetric unit