Nidovirus RNA polymerases: Complex enzymes handling exceptional RNA genomes.

摘要: Coronaviruses and arteriviruses are distantly related human animal pathogens that belong to the order Nidovirales. Nidoviruses characterized by their polycistronic plus-stranded RNA genome, production of subgenomic mRNAs conservation a specific array replicase domains, including key RNA-synthesizing enzymes. (26-34 kilobases) have largest known genomes replication presumably requires processive RNA-dependent polymerase (RdRp) enzymatic functions suppress consequences typically high error rate viral RdRps. The significantly smaller form an intriguing package with coronaviruses analyse RdRp evolution function. domain nidoviruses resides in cleavage product polyprotein named non-structural protein (nsp) 12 nsp9 arteriviruses. In all nidoviruses, C-terminal is linked conserved N-terminal domain, which has been coined NiRAN (nidovirus RdRp-associated nucleotidyl transferase). Although no structural information available, functional characterization nidovirus larger enzyme complex it part, progressed over past decade. several smaller, non-enzymatic nsps were direct function, while 3'-to-5' exoribonuclease activity nsp14 was implicated fidelity. arteriviruses, nsp1 subunit found maintain balance between genome mRNA production. Understanding behaviour interactions during synthesis subsequent processing will be rationalising evolutionary success development antiviral strategies.