Detection of RNA-protein Complex in Vaccinia Virus Core in Vitro Transcription System

The incubation of vaccinia virus cores in appropriate conditions promotes the release of core proteins into a supernatant fraction. Under transcription assay conditions core mRNAs are extruded in association with viral core proteins, however the presence of these proteins within the core particle is not essential for RNA synthesis and extrusion. The RNA-protein complex is resistant to micrococcal nuclease. Five proteins of 60K, 43K, 28K, 18K and 14.5K with RNA-binding abilities have been identified by [32P]RNA overlay protein blot assays. These proteins are likely to be a component of the viral ribonucleoprotein complex since core basic proteins with similar MrS have been identified and at least one RNA-binding protein is predicted in the vaccinia virus genome.