ENHANCEMENT OF NEUROSPORA VS RIBOZYME CLEAVAGE BY TUBERACTINOMYCIN ANTIBIOTICS

Several examples of inhibition of the function of a ribozyme or RNA-pr otein complex have shown that certain antibiotics can interact specifi cally with RNA. There are, however, few examples of antibiotics that h ave a positive, rather than a negative, effect on the function of an R NA. We have found that micromolar concentrations of viomycin, a basic, cyclic peptide antibiotic of the tuberactinomycin group, enhance the cleavage of a ribozyme derived from Neurospora VS RNA. Viomycin decrea ses by an order of magnitude the concentration of magnesium required f or cleavage, It also stimulates an otherwise insignificant trans-cleav age reaction by enhancing interactions between RNA molecules. The abil ity of viomycin to enhance some RNA-mediated reactions but inhibit oth ers, including translation and Group I intron splicing, demonstrates t he potential for natural selection by small molecules during evolution in the 'RNA world' and may have broader implications with respect to ribozyme expression and activity in contemporary cells.