Molecular genetics of pestiviruses.

Recent developments in understanding the molecular genetics of pestiviruses are reviewed. The genomic RNA of several pestiviruses has been molecularly cloned and sequenced. The genetic organization of the viral protein coding region has been refined, and the complete complement of virus-encoded proteins has been elucidated. Viral gene expression involves both co-translational and post-translational precursor polyprotein processing. Biogenesis of the virion structural proteins requires the proteolytic activity of the first protein of the open reading frame (p20), as well as host cell enzymes. A second virus-encoded proteinase (p80) is required for processing viral nonstructural proteins. Molecular and biochemical data indicate pestiviruses share many features with both the flaviviruses and human hepatitis C viruses, while at the same time, also reveal their distinct nature.