Abstract
Experiments demonstrate that Q[beta]-replicase can be separated into a "heavy" and a "light" component in sucrose gradients. The heavy is about 130,000 and the light 80,000 in molecular weight. In isolation, neither component can initiate the reaction when challenged with intact normal Q[beta]-RNA. Full activity is reconstituted in a mixture of the 2. The heavy component can synthesize poly G if poly C is provided as a template.