Sequence analysis of the putative structural genes of hepatitis C virus from Japanese and European origin.

cDNA fragments encoding the putative structural genes of the hepatitis C genome were isolated from a plasma pool of Japanese non-A, non-B hepatitis patients and from sera of individual Spanish patients. From the Japanese plasma pool a series of E1 clones was obtained that showed 88-98% homology among each other, both at the nucleotide and amino acid level. Compared to the sequences published by the Chiron Corporation and Takeuchi et al., the amino acid homology was 75-79% and 91-94%, respectively. Analysis of the core and E2/NS1 genes showed a high conservation of the core sequence and a high sequence variation in the 5' end of the E2/NS1 gene. The E1 gene of one Spanish isolate showed greater homology to the Chiron than to the Japanese sequence. Another Spanish isolate was more homologous to the Japanese sequence indicating that both hepatitis C genotypes are present in Europe. Analysis of the E1 gene of an isolate derived from a single patient with a 5-year interval revealed nine nucleotide and five amino acid changes.