[Primary structure and variability of partial sequences in nonstructural gene 5 region of hepatitis G virus]

To sequence partial genome of hepatitis G virus (HGV) in the sera of patients with different chronic liver disease and paid donors.

Total nucleic acids were extracted from the sera of 3 paid donors, 2 patients with liver cirrhosis, and 1 patient with non-A-E chronic hepatitis, then subjected to reverse transcriptase-nested-polymerase chain reaction (PCR) with primers derived from the putative nonstructural gene 5 (NS5). PCR products were directly sequenced after purification.

Partial HGV NS5 gene of 6 isolates exhibited 87.2% to 93.9% nucleotide sequence identities with 3 reported HGV isolates (GBV-C, PNF2161, R10291) while the nucleotide homologies among the 6 isolates were 90.1% to 93.8%. And 93.6% to 98.7 homolies were found at the deduced amino acid level when comparing the 6 isolates with 3 reported ones, while 93.61% to 98.40% amino acid identities were found among 6 isolates. In the region sequenced, there were 16 conserved proline residues and 8 conserved cysteine residues.

Six isolates of HGV were obtained from different cases and donors. The partial nucleotide sequences, as well as amino acid sequences, of the putative NS5 region of HGV were relatively conserved. This region of the genome may be suitable for the development of diagnosis reagents.