RNA-Dependent RNA Polymerases of Picornaviruses: From the Structure to Regulatory Mechanisms

RNA-Dependent RNA Polymerases of Picornaviruses: From the Structure to Regulatory Mechanisms

RNA viruses typically encode their own RNA-dependent RNA polymerase (RdRP) to ensure genome replication within the infected cells. RdRP function is critical not only for the virus life cycle but also for its adaptive potential. The combination of low fidelity of replication and the absence of proofreading and excision activities within the RdRPs result in high mutation frequencies that allow th...

RNA Dependent RNA Polymerases: Insights from Structure, Function and Evolution

RNA dependent RNA polymerase (RdRp) is one of the most versatile enzymes of RNA viruses that is indispensable for replicating the genome as well as for carrying out transcription. The core structural features of RdRps are conserved, despite the divergence in their sequences. The structure of RdRp resembles that of a cupped right hand and consists of fingers, palm and thumb subdomains. The catal...

RNA-dependent RNA Polymerases of Cystoviruses

RNA-dependent RNA polymerases of plants.

The existence of RNA-dependent RNA polymerases (EC 2.7.7.48) in plants has been definitely proven by their isolation in pure form from cucumber and tobacco in our laboratory and from cowpea at Wageningen. These enzymes are single-chain proteins of 100-130 kilodaltons. They show clear physical and biochemical differences characteristic for a given plant species, even when their amounts in the pl...

RNA-dependent RNA polymerases, viruses, and RNA silencing.

Most viruses have RNA genomes that are replicated and transcribed into messenger RNA by viral RNA-dependent RNA polymerases (RdRps), usually in concert with other viral and host factors. Many, if not most, eukaryotes also encode putative RdRps that have been implicated in sequence-specific, RNA-triggered gene silencing. Although the viral and cellular RdRps have no sequence homology, they share...