Dimers of 5 S RNA and 5.8 S RNA in low molecular weight RNA preparations

Abstract

When purified 5 S RNA is exposed to concentrated solutions of sodium chloride or sodium phosphate, it is partly converted to the 5′ S conformer but also partly to dimers and oligomers of 5 S RNA which are stable during gel filtration and electrophoresis. Presence of 5 S dimers can not be demonstrated in cellular RNA preparations extracted with phenol. 5.8 S RNA dimers are observed in RNA from cells extracted with phenol at 40–60°C. No 5.8 S dimer is observed when RNA is extracted at 0°C. The amount of dimer increases with the temperature of extraction and may account for about 10% of the total 5.8 S RNA. When RNA extracted at 40–60°C is electrophoresed on polyacrylamide gels under nondenaturing conditions the 5.8 S RNA dimer co-migrates with the low molecular weight RNA component L.