Effect of 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole on the synthesis of low molecular weight RNA components

The synthesis of low molecular weight RNA components D, C and A is more inhibited by 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole than the synthesis of ribosomal RNA, which in turn is more inhibited than that of tRNA and 5S RNA. The differential inhibitory effect of 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole is most pronounced at low concentrations. The results support the conclusion that D, C and A are products of polymerase II, and suggest that the D, C and A transcripts are derived from large size heterogeneous nuclear RNA. Components K and L are inhibited like tRNA and 5S RNA and are thus probably synthesized by polymerase III.