The present invention relates generally to the fields of biochemistry, molecular biology, and virology. More particularly, it relates to the identification of 259 nucleotides located at the 3' end of the GB virus B (GBV-B) genome. The invention involves nucleic acid constructs and compositions encoding GBV-B sequence, including the 3' end of the sequence, which has allowed an infectious GBV-B clone to be constructed. This construct, and chimeric versions of it, may be employed to study GBV-B and related hepatitis family members, such as hepatitis C virus. The invention thus includes methods of preparing GBV-B-containing sequences, constructs, and viruses, as well as methods of employing these compositions.