Characterization of transcriptase and replicase particles isolated from reovirus-infected cells

Double-stranded RNA-dependent single-stranded RNA polymerase (transcriptase) and single-stranded RNA-dependent double-stranded RNA polymerase (replicase) were isolated from reovirus-infected cells. Both transcriptase and replicase were associated with subviral particles that could be separated by velocity sedimentation in glycerol density gradients and by equilibrium sedimentation in CsCl density gradients. The transcriptase particles (ϱ = 1.42 g/cm 3) which sedimented at approximately 220 S contained double-stranded RNA and the virus-specific polypeptides λ1, λ2, μ0, and σ2. The majority of the replicase particles (ϱ = 1.35 g/cm 3) sedimented at approximately 180 S. These particles were composed of single-stranded, partially double-stranded and double-stranded RNA and the virus-specific polypeptides λ1, λ2, μ2, σ1, σ2, and σ3. Both particles were approximately 40 nm in diameter.