Ribosomes and their subunits have been isolated from Halobacterium marismortui, an extremely halophilic bacterium from the Dead Sea. The stability and functional activity of the subunits were tested under a wide range of salt conditions. Three‐dimensional microcrystals of the large ribosomal subunits have been obtained. Electron microscopy of positively stained thin sections of these crystals showed that the particles are closely packed with approximate cell constants of 310 × 350 Å.

No abstract

A new form of thr~-dimensioM1 crystals of the 50 S ribosomal subunits from Haiobacterium m~~mortui has been obtained at 19"C, using ~iyethyle~e glycol in the presence of 1.2-1.7 M KC1 in the crystall~tion mixture. The crystals diffract X-rays to 13 A and are stable in the synehrotron radiation beam for 4-8 h. Being aggregates of thin plates, the dimensions of only two unit cell edges, 147 x 181 A, with an angle of 95", could so far be determined by both X-ray crystallography and electron microscopy. Attempts to produce thicker crystals by sophisticated seeding are in progress. Ribosomes (Halobacteria) CrystallizationSynchrotron radiation