抄録
The degradation of RNA was induced during incubation of Escherichia coli cells in 0.01M Tris buffer containing 0.15M sodium chloride (0.15M NaCl-Tris buffer). After incubation in 0.15M NaCl-Tris buffer for 120min, approximately 50% of RNA was lost from the acid insoluble fraction. When magnesium (50mM) was added to 0.15M NaCl-Tris buffer, the degradation of RNA was completely prevented. When crude ribosomes, which were prepared by sonic disruption of the cells, were incubated in 0.15M NaCl-Tris buffer, RNA was rapidly degraded but the addition of magnesium (5mM) again prevented the degradation of RNA. 3'-Mononucleotides, but not 5'-mononucleotides, were determined as the main degradation products of cellular RNA. When E. coli Q 13, a mutant deficient in ribonuclease (RNase) I, was treated in a similar fashion, no degradation of RNA occurred. These results suggest that the degradation of RNA during incubation in 0.15M NaCl-Tris buffer is due to the enzymatic action of RNase I.
