Abstract
Coronavirus replication and transcription are processes mediated by a protein complex, with the RNA-dependent RNA polymerase (RdRp) as a main component. Proteomic analysis of highly purified transmissible gastroenteritis virus showed the RdRp to be a component of the viral particles. This finding was confirmed by Western blotting, immunofluorescence, and immunoelectron microscopy analyses. Interestingly, the replicase nonstructural proteins 2, 3, and 8 colocalized with the RdRp in the viral factories and were also incorporated into the virions.