title: Variant of hepatitis B virus isolated in Zimbabwe.
abstract: The polymerase chain reaction (PCR) was used to amplify an approximately 1.2 kb DNA fragment encompassing the pre-S/S gene region of HBV DNA from serum of patients with acute hepatitis B virus infection. Nucleotide sequence analysis revealed a number of interesting features in the S gene region. Two Bam HI sites were located at nucleotide positions 557 and 872, respectively, in the S gene. Guanine (G) was found at nucleotide position 903 as part of AGA, the codon for arginine (R) corresponding to amino acid position 122 of the S protein. Adenine (A) was found at nucleotide position 1017 as part of AAA, the codon for lysine (K) corresponding to amino acid position 160 of the S protein. Nucleotide sequence alignment revealed a 97% homology to the corresponding domain of an HBVadw genome (clone pFDW294). Within the second loop of the "a" determinant, two mutations resulting in substitution of serine or threonine with the hydrophobic amino acids, methionine at position 143 and with alanine in place of glycine at position 145, are predicted from the consensus nucleotide sequence of the PCR-derived clones. Subtyping with monoclonal antibodies showed that the HBsAg was of the ayw subtype.
authors.affiliation: Department of Biochemistry, University of Zimbabwe, Harare.
authors.forename: M M
authors.initials: MM
authors.lastname: Chirara
authors.forename: C J
authors.initials: CJ
authors.lastname: Chetsanga
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D004279:DNA, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005814:Genes, Viral; D014644:Genetic Variation; D006509:Hepatitis B / Q000382:microbiology*; D006514:Hepatitis B Surface Antigens / Q000737:chemistry / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D015030:Zimbabwe
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; C050806:presurface protein 1, hepatitis B surface antigen; C050807:presurface protein 2, hepatitis B surface antigen