[gamma-Irradiated ribosomes from Micrococcus radiodurans in a cell-free protein synthesizing system (author's transl)].

gamma-irradiation inactivation of isolated ribosomes of Micrococcus radiodurans was studied by examining poly U directed synthesis of polyphenylalanine. Ribosomes of M. radiodurans did not show significant gamma-radiation sensitivity up to a dose of approx. 11.6 k Gy. Cells of M. radiodurans take up more magnesium than E. coli cells unter the same conditions. The magnesium content of ribosomes of M. radiodurans was 18% higher than that of E. coli ribosomes. A possible relation between Mg2+-content and gamma-resistance is discussed.