Virus-associated enzymes

Abstract Many viruses have associated enzyme activity which in some cases, particularly the RNA viruses and poxviruses, is clearly essential to initiate virus replication. The detailed mechanisms of the transcription of viral genomes by associated RNA polymerases still require elucidation despite the considerable progress already made. With increasing complexity in the DNA viruses, one finds a more complex array of associated enzymes. Except for the poxvirus transcriptase no definite function has been established for other DNA virus associated enzymes.