The open reading frame 2 initiation site of genotype 4 hepatitis E virus (HEV)

摘要

Recently, Fu et al. (2011) sequenced the full length genome of a genotype 4 swine hepatitis E virus (HEV) strain, CHN-XJ-SW13. The genome was compared to 90 HEV strains representing genotypes 1–4 retrieved from GenBank in an effort to identify sequences putatively responsible for differences in the host range of the virus, and the severity of the disease caused by genotypes 1 and 2 compared with genotypes 3 and 4. However, in regard to open reading frame 2 (ORF2), these authors mistakenly referred to the previously presumed ORF2 initiation strategy in which ORF2 utilizes the AUG start codon that overlaps the ORF1 stop codon. Consequently, the length of the genotype 4 ORF2 and the location of the conserved amino acid sites in the ORF2 protein from genotypes 1-2 and 3-4 are quoted incorrectly. The actual length of ORF2 is 1983 nt (encoding for a structural protein consisting of 661 amino acids) and not 2025 nt. Accordingly, the locations of specific amino acid substitutions sites (relating to CHN-XJ-SW13 strain, accession number: GU119961) in genotypes 1-2 and 3-4 are 5, 91, 117, 483, 492, 497 and 599 instead of 19, 105, 131, 497, 506, 511 and 613, respectively.