Sequence analysis of the bicistronic Drosophila X virus genome segment A and its encoded polypeptides
Sequence analysis of the bicistronic Drosophila X virus genome segment A and its encoded polypeptides
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DOI：
10.1006/viro.1996.0610
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发表时间：
1996-11-15
期刊：
影响因子：
3.7
通讯作者：
Dobos, P
中科院分区：
文献类型：
--
作者：
Chung, HK;Kordyban, S;Dobos, P
果蝇X病毒代表双RNA病毒科的昆虫双RNA病毒属。对该含有双片段dsRNA的病毒的A片段进行克隆和测序。3360 bp长的核苷酸序列显示存在两个开放阅读框（ORF）。一个3096个核苷酸的大ORF，其两侧是107-bp的5 '和157-bp的3'非翻译区，以及一个711个核苷酸长的小ORF，其位于大ORF的羧基一半内，但在不同的阅读框中。大的ORF编码114-kDa的多蛋白，其被病毒编码的蛋白酶VP 4互补加工以产生preVP 2、VP 3和VP 4（VP 1由基因组区段B编码）。VP3和VP4的N-末端氨基酸测序确定了多蛋白内的顺序NH2-preVP2-VP4-VP3-COOH。小ORF跨越VP4/VP3连接，能够编码一种碱性的、富含精氨酸的27-kDa多肽，该多肽迄今为止尚未在感染细胞中检测到。将由两个ORF指定的氨基酸序列与代表双RNA病毒科的另外两个属（水双RNA病毒和禽双RNA病毒）的传染性胰腺坏死病毒（IPNV）和传染性法氏囊病病毒（IBDV）的氨基酸序列进行比较。三种病毒之间的显着序列同源性被发现被限制到preVP2的氨基和羧基区域和VP3的羧基末端区域附近的一个小的21个残基长的结构域。三种病毒的小ORF显示出显著的序列同源性。(C)出版社：Academic Press，Inc.
Drosophila X virus represents the entomobirnavirus genus of the Family Birnaviridae. Segment A of this bisegmented dsRNA containing virus was cloned and sequenced. The 3360-bp-long nucleotide sequence revealed the presence of two open reading frames (ORFs). A large ORF of 3096 nucleotides, which is flanked by a 107-bp 5' and a 157-bp 3'-untranslated region, and a 711-nucleotide-long small ORF located within the carboxy half of the large ORF but in a different reading frame. The large ORF encodes a 114-kDa polyprotein which is cotranslationally processed by the virus-coded protease VP4 to generate preVP2, VP3, and VP4 (VP1 is encoded by genome segment B). N-terminal amino acid sequencing of VP3 and VP4 established the order NH,(2)-preVP2-VP4-VP3-COOH within the polyprotein. The small ORF straddles the VP4/VP3 junction and is capable of encoding a basic, arginine-rich 27-kDa polypeptide which so far has not been detected in infected cells. The amino acid sequences specified by the two ORFs were compared to those of infectious pancreatic necrosis virus (IPNV) and infectious bursal disease virus (IBDV) that represent the two other genera (aquabirnavirus and avibirnavirus) of the Birnaviridae family. Significant sequence homology among the three viruses was found to be restricted to the amino and carboxy regions of preVP2 and to a small 21-residue-long domain near the carboxy terminal region of VP3. significant sequence homology is exhibited by the small ORFs of the three viruses. (C) 1996 Academic Press, Inc.