CRYSTALS OF 70S RIBOSOMES FROM THERMOPHILIC BACTERIA ARE SUITABLE FOR X-RAY-ANALYSIS 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 synchrotron X-ray beam, these crystals diffract to 19 angstrom and 35 angstrom, respectively, and can be irradiated at temperatures of 110-120 K for days without noticeable decay. Diffraction data sets to 22 angstrom and to 33 angstrom with reasonable R scale were collected from the crystals of 70S from T. thermophilus. The cell dimensions (a = b = 524 angstrom, c = 315 angstrom), the symmetry (P4(1)2(1)2 or P4(3)2(1)2) and the density (1.063 g/cm3) of these crystals indicate that there is one 70S ribosome per asymmetric unit.