Some Properties of Ribosomes from Myxobacter 495

Abstract

The ribosomes of Myxobacter 495 are similar to other bacterial ribosomes in that the 70 S monomer is made up of a 50 S subunit (containing 23 S and 5 S RNA) and a 30 S subunit (containing 16 S RNA). The base composition of the ribosomal RNA is very similar to that of E. coli. The Myxobacter 495 ribosomes contain nucleases that are not removed by washing with 1 M (NH4)2SO4 and which are relatively insensitive to inhibition by Macaloid or sodium dodecyl sulfate. Only in the presence of diethyl pyrocarbonate was it possible to isolate intact 16 S and 23 S RNA. The (NH4)2SO4-washed ribosomes were much less stable than the unwashed ribosomes due apparently to activation of a nuclease which was located mainly in the 30 S subunit.