Sequence analysis of putative structural regions of hepatitis C virus isolated from 5 Japanese patients with hepatocellular carcinoma.

The nucleotide sequences of the 5'-portion of the HCV genome, consisting of 2672 nucleotides, were determined by analysis of clones derived from 5 different patients with liver cirrhosis and hepatocellular carcinoma. Comparison of 5 genomes and 8 isolates already reported demonstrated the significant genome diversity in the structural regions. Genetic divergence was outstanding in the envelope regions (E1 and NS1/E2, > 59.7% identity) in contrast to the sequence conservation of the 5' non-coding (> 93.8% identity) or core regions (> 82.0% identity). Although hypervariable regions were found in the NS1/E2 region as reported, hydropathicity was maintained for all clones, reflecting the biological functions of these regions.