title: Characteristics of the X gene of hepatitis B virus.
abstract: The 465-nucleotide sequence of the X gene from our cloned hepatitis B virus (HBV) DNA (subtype adw) was determined and compared to the same gene of 10 other published HBV sequences (3 of adw, 4 of adr, 2 of ayw, and 1 of ayr). We found (i) a total of 56 base differences among the 11 sequences (without counting the 27-base deletion in one adr) which resulted in 88% nucleotide homology, and (ii) 5 pairs of repeated sequence (3 direct repeats and 2 inverted repeats) that were highly conserved. Comparison of the protein amino acid sequences indicated that (i) there is 80% amino acid homology in total, and (ii) there are four highly conserved cysteine residues. In addition, the X gene of the adw subtype is more conserved than that of adr.
authors.affiliation: Graduate Institute of Microbiology and Immunology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.
authors.forename: S J
authors.initials: SJ
authors.lastname: Lo
authors.forename: M L
authors.initials: ML
authors.lastname: Chien
authors.forename: Y H
authors.initials: YH
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics*; D005814:Genes, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral