A putative new domain target for anti-hepatitis B virus: residues flanking hepatitis B virus reverse transcriptase residue 306 (rtP306).
Previous work showed that conservation of proline at residue 306 (rtP306) of hepatitis B virus (HBV) reverse transcriptase (RT) is crucial for virus replication and encapsidation of pregenomic RNA (pgRNA). In this study, the functions of residues flanking rtP306 in HBV RT (rtG304, rtY305, rtA307, rtL308 and rtL311) are presented. Alanine or phenylalanine was used to substitute these residues by constructing site-directed mutants which were used to transfect Huh-7 cells. Replication competencies and encapsidation efficiencies were compared between the mutants and the parental viral strain. Substitutions at these residues resulted in marked decrease of replication competency, which was confirmed by Southern blot hybridization of HBV DNA isolated from intracytoplasmic core particles, and trans-complementation between a non-replicative defective mutant and corresponding RT mutants. Impaired pgRNA encapsidation efficiency of these mutants was shown as the major mechanism for decreased replication efficiency. Since residues from rt304 to rt311 are highly conserved among genotypes A-H HBV strains, results suggest that rt304 to rt311 in HBV RT may serve as a putative anti-HBV new target domain.
Wang
Yong-Xiang
YX
Key Laboratory of Medical Molecular Virology, Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, PR China.
Xu
Xiang
X
Luo
Cheng
C
Ma
Zhang-Mei
ZM
Jiang
Hua-Liang
HL
Ding
Jian-Ping
JP
Wen
Yu-Mei
YM
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D015152:Blotting, Northern; D015139:Blotting, Southern; D045744:Cell Line, Tumor; D017124:Conserved Sequence; D004279:DNA, Viral / Q000032:analysis; D005816:Genetic Complementation Test; D005838:Genotype; D006515:Hepatitis B virus / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D017434:Protein Structure, Tertiary; D012194:RNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D019065:Virus Assembly / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology*
D004279:DNA, Viral; D012194:RNA-Directed DNA Polymerase