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Selective inhibition of the reverse transcription of duck hepatitis B virus by binding of 2′,3′‐dideoxyguanosine 5′‐triphosphate to the viral polymerase
Author(s) -
Howe A Y,
Robins M J,
Wilson J S,
Tyrrell D L
Publication year - 1996
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.510230113
Subject(s) - duck hepatitis b virus , reverse transcriptase , dna polymerase , polymerase , hepatitis b virus dna polymerase , biology , microbiology and biotechnology , virology , primer (cosmetics) , transcription (linguistics) , dna replication , hepatitis b virus , viral replication , dna , virus , hepadnaviridae , chemistry , polymerase chain reaction , biochemistry , gene , linguistics , philosophy , organic chemistry
Hepatitis B virus (HBV) replication is mediated by the viral polymerase that possesses three functional domains: primer, DNA polymerase/reverse transcriptase, and RNase H. Using the Pekin duck as an animal model, we demonstrate a novel mechanism of inhibition of duck hepatitis B virus (DHBV) by 2,6‐diaminopurine 2′,3′‐dideoxyriboside (ddDAPR), a prodrug of 2′,3′‐dideoxyguanosine (ddG). A selective and irreversible inhibition of DHBV DNA replication is found in ducklings treated with high doses of ddDAPR (20 to 50 mg/kg), but not with similar doses of 2′,3′‐dideoxycytidine (ddC). The inhibition mediated by ddDAPR occurs at a very early stage of the reverse transcription. Despite the inhibition of DHBV DNA replication by ddDAPR, the DNA polymerase and reverse transcriptase activities of the polymerase are found to remain active when tested on exogenous templates in activity gels. We have demonstrated direct binding of [α‐ 32 P]ddGTP to the DHBV polymerase expressed in an in vitro transcription and translation system. These results suggest that the binding of ddGTP to the polymerase blocks the initial DNA replication.