Hepatitis E virus genome. Molecular features, expression of immunoreactive proteins and sequence divergence.

The strategy for molecular cloning of hepatitis E virus (HEV), the major etiologic agent of enterically-transmitted non-A, non-B hepatitis, is briefly described. The organization of the HEV genome is discussed and compared to those of two other vertebrate viruses that contain single-stranded, positive-sense, polyadenylated RNA genomes with three overlapping ORFs. Serologic cross-reactivity of expressed proteins and genetic divergence of HEV isolates are also described within the context of sequence variation, type-common epitopes, and type-specific epitopes.