Viral DNA synthesis.
Viral DNA synthesis.
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病毒DNA合成。
DOI：
10.1007/978-3-642-76015-0_3
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发表时间：
1991
影响因子：
--
通讯作者：
Mason,WS
中科院分区：
文献类型：
--
作者：
Seeger,C;Summers,J;Mason,WS
In 1973, it was first discovered that human hepatitis B virus (HBV) preparations from sera of chronically infected individuals contain an endogenous polymerase activity capable of carrying out a repair reaction on the viral DNA template in the presence of magnesium and nucleotide triphosphates (Kaplanet al. 1973). The polymerase was shown to be resistant to solubilization by nonionic detergents, a condition precluding the characterization of enzymatic activities with exogenous RNA or DNA templates. With the help of electron microscopic characterization of the predominant species in virus preparations (Robinsonet al. 1974), together with sedimentation and electrophoretic analysis of the DNA products of the endogenous polymerase reaction (Kaplanet al. 1973; Summerset al. 1975), the structure of the viral genome was identified. HBV has a ca. 3 kbp-long genome held in a relaxed circular conformation by a short, cohesive overlap (ca. 0.2 kbp) between the 5′ ends of the two DNA strands (Summerset al. 1975; Sattlerand Robinson1979; Ganemet al. 1982; Molnar-Kimberet al. 1984). One strand, subseqently shown to encode the viral proteins and hence termed minusstrand DNA (Paseket al. 1979), is complete whereas the other strand, plus-strand DNA, is incomplete and heterogeneous in length (Summerset al. 1975). Thus, the repair reaction carried out by the endogenous polymerase in vitro fills in the single-stranded gap, which can span up to 50% of the viral genome. These characteristics of the HBV genome have served, along with other criteria, to identify additional members of the hepadnaviral family, including woodchuck hepatitis virus (WHV) (Summerset al. 1978), ground squirrel hepatitis virus (GSHV) (Marionet al. 1980), duck hepatitis B virus (DHBV) (Masonet al. 1980), and heron hepatitis B virus (HHBV) (Sprengelet al. 1988).
