Molecular cloning of an Australian isolate of hepatitis C virus

Summary.  The genomic sequence of an Australian isolate of hepatitis C virus (HCV) was determined from overlapping cDNA clones obtained from a small amount (1.2 ml) of serum from a single individual with hepatitis C. The isolate (HCV-A) comprises 9 379 nucleotides (nt) including 324 nt of a 5′ untranslated region (5′UTR), a single long open reading frame of 9 033 nt encoding a polyprotein of 3 010 amino acids (aa), and 22 nt of a 3′ untranslated region (3′UTR). Sequence analysis of a 251 nt region within the 5′UTR and a 222 nt region within NS5B showed the genotype of HCV-A to be subtype 1b. A striking difference in the amino acid sequence of the hypervariable region 1 (HVR-1), and not in the surrounding sequence, was seen in cDNA clones synthesised from serum taken 52 weeks after the initial sample, indicating a significant population diversity of HCV genomes. Accepted October 17, 1977 Received July 7, 1997