Biophysical studies of reovirus type 3. III. A laser light-scattering study of the RNA transcriptase reaction.

Abstract

Abstract The synthesis of reovirus messenger RNA by reovirus cores has been studied in vitro by a laser self-beat spectroscopy method capable of measuring diffusion coefficients at intervals of 2 min to a relative precision of greater than ±1%. Using this method the synthesis of RNA by cores has been followed by the change in diffusion coefficient that results from the increased frictional drag on the core caused by the attached nascent messenger-RNA molecules. A study of the kinetics of the reaction indicated that a lag occurred after activation before the effective hydrodynamic radius of the core increased, even though synthesis of RNA by the core begins immediately upon the activation temperature being reached. The length of the lag period is a function of the temperature and hence the rate of synthesis, and it appears to represent the time taken for the nascent RNA strand to reach the surface of the core. No change was detected in the hydrodynamic properties of the core particle itself, following activation of the RNA transcriptase, indicating that activation does not significantly alter the structure of the particle.