Double-Stranded Ribonucleic Acid Formation in vitro by MS 2 Phage-Induced RNA Synthetase

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Science  29 Nov 1963:
Vol. 142, Issue 3596, pp. 1188-1191
DOI: 10.1126/science.142.3596.1188


Part of the RNA synthesized from nucleoside triphosphate precursors by partially purified RNA synthetase, an enzyme induced in Escherichia coli by the RNA-containing phage MS 2, is resistant to hydrolysis by ribonuclease. Upon heating in 0.15M sodium chloride, 0.015M sodium citrate followed by fast cooling the material becomes ribonuclease-sensitive with a sharp transition at 102° to 104° C. The suggestion that the ribonuclease-resistant product is double-stranded RNA is reinforced by restoration of the ribonuclease resistance of the heat-denatured material by reannealing at temperatures just below the transition point and by its buoyant density in cesium sulfate. It is suggested that double-stranded RNA is the replicative form of MS 2 phage RNA.