As. Muerhoff et al., SEQUENCE HETEROGENEITY WITHIN THE 5'-TERMINAL REGION OF THE HEPATITISGB VIRUS-C GENOME AND EVIDENCE FOR GENOTYPES, Journal of hepatology, 25(3), 1996, pp. 379-384
associated with hepatitis in humans, GB virus C bears some resemblance
to hepatitis C virus in its genomic sequence and organization, Howeve
r, unlike hepatitis C virus, an open reading frame possessing a comple
te core protein was not identified in the original isolate, Methods: T
o verify the sequence at the 5'-end of the GB virus C genome, we ampli
fied approximately 600 nucleotides from this region from 35 globally d
istributed individuals, The nucleotide sequences were translated in al
l possible reading frames and then examined for conserved motifs indic
ative of nucleocapsid or core-like peptides, Results: Forty-two unique
GB virus C sequences were obtained from the 35 individuals, The deduc
ed amino acid sequences upstream of the putative Fl gene from each iso
late varied in length and composition, such that a conserved core-like
sequence was not apparent; No core-like sequences were evident in the
other reading frames, There was, however, a single methionine codon h
eld in common among all isolates, although it was located very near th
e presumed amino-terminus of the putative Fl protein, Further analysis
of the sequences for their evolutionary relatedness demonstrated the
existence of five GB virus C subtypes that demonstrated a significant
correlation with geographic distribution, Conclusions: GB virus C diff
ers from hepatitis C virus and GB virus B in that it does not encode a
nucleocapsid or core protein, The existence of GB virus C subtypes em
phasizes the importance of investigating the correlation between infec
ting subtype and the severity of liver disease and/or responsiveness t
o treatment of GB virus C-associated hepatitis.