丁型肝炎病毒(HDV)是环状单股负链的人类缺陷性RNA病毒,其基因组全长1.7kb。迄今发现HDV只表达一种功能性结构蛋白——HDAg,但以2种不同形式存在,即195个氨基酸的小HDAg(δAg-S)和214个氨基酸的大HDAg(δAg-L)。虽然大HDAg仅在其C端比小HDAg多19个氨基酸,但大HDAg和小HDAg却表现截然不同的功能:小HDAg反式激活HDV RNA的复制,而大HDAg则通过显性失活的反式调节作用抑制HDV RNA复制,但大HDAg却为HDV完整病毒颗粒的包装所必需。尽管目前已在HDAg中规定了与其反式调节作用密 Hepatitis D virus (HDV) is a circular, single-stranded, negative human RNA virus whose genome is 1.7 kb in length. To date, HDV has been shown to express only one functional structural protein, HDL, but exists in two different forms, namely a small HDAg of 195 amino acids (δAg-S) and a large HDAg of 214 amino acids (δAg-L). Although large HDAg has only 19 amino acids more C-terminal than small HDAg, large HDAg and small HDAg exhibit distinct functions: small HDAg transactivates the replication of HDV RNA whereas large HDAg passes dominant negative Regulatory effects inhibit HDV RNA replication, but large HDAg is necessary for the packaging of HDV complete virions. Although it has been established in HDAg with its trans-regulatory role in dense