Crystals of wild-type, mutated, derivatized and complexed 50 S ribosomal subunits from Bacillus stearothermophilus suitable for X-ray analysis

Abstract Three-dimensional single crystals of wild-type and mutated 50 S ribosomal subunits from Bacillus stearothermophilus , as well as crystals of reconstituted subunits containing heavy-atom clusters and complexes of these subunits with tRNA and a short nascent polypeptide chain, were grown from polyethylene glycol in the presence of salts at low concentrations. Within experimental error, all these crystals are isomorphous, packed with monoclinic symmetry ( C 2) in unit cells of a = 300 A , b = 546 A , c = 377 (±1%) A and β = 112 ° . Using synchrotron radiation at 85 to 100 K they diffract to 11 A resolution and can be irradiated for hours without disintegrating, so that a complete data set could be collected from a single crystal.