Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 66

Although the genomes of viruses come in a number of configurations, they share a common requirement: they must be efficiently copied into mRNAs for the synthesis of viral proteins and progeny genomes for assembly. The synthesis of RNA molecules in cells infected with RNA viruses is a unique process that has no counterpart in the cell (see Chapter 6). With the exception of retroviruses, all RNA viruses encode an RNA-dependent RNA polymerase to catalyze the synthesis of both mRNAs and genomes. For the majority of DNA viruses and retroviruses, synthesis of viral mRNA is accomplished by RNA polymerase II, the enzyme that produces cellular mRNA (see Chapter 7). Much of our current understanding of the mechanisms of cellular transcription comes from study of the transcription of viral templates.