 BackResearch Article ScienceAsia 24 (1998): 155-167 |doi: 10.2306/scienceasia1513-1874.1998.24.155 CLONING AND SEQUENCE ANALYSIS OF HEPATITIS B VIRUS GENOME OF ADR SUBTYPE ISOLATED IN THAILANDPATAMA MONKONGDEEa, CHUENCHIT BOONCHIRDb, KRUAVON BALACHANDRAc, DUANTHANOM THAWARANANTHAc, JITTAPORN WATANASEREEd AND SOMSAK PANTUWATANAaABSTRACT: Hepatitis B virus (HBV) DNA derived from Dane particle of subtype adr was successfully cloned into the plasmid pBluescript. The virus was recovered from blood specimens donated to the Thai Red Cross. Its complete nucleotide sequence was determined. The 3,215 bp sequence showed the presence of open reading frames (ORF) including the genes coding for hepatitis B surface antigen (HBsAg) and pre-hepatitis B surface antigen (pre-S), P protein, hepatitis B core antigen (HBcAg) and X proteins. The HBsAg had 226 amino acids while the pre-S comprised of 174 amino acids. The P polypeptide comprised of 843 amino acids whereas HBcAg was consisting of 212 amino acids. The X protein comprised of 154 amino acids. It was found that all of the direct repeat of the undecanucleotide sequence (DR1) and the two small direct repeat sequences (DR2 and DR3) were characteristic structures of HBV DNA. Analysis of deduced amino acid sequences in the HBsAg revealed that the 9 amino acids of antigenic determinant a, 139-CTKPSDGNC-147, of this clone were conserved. The Cys-124 and Cys-147 together with Pro-142 required for full antigenicity were also observed. According to comparison of the amino acid sequences in the HBsAg sequence, the genotype of cloned HBV was classified as group C. In addition, the presence of Val-177 and Pro-178 in the HBsAg indicated that the cloned HBV had q subtype determinant. The amino acid seq4ences proposed to be immunodominant in the pre-S2 region, 131-LLDPRVRGLYFPAG-144, were found. a Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400 Received July 22, 1998
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