NUCLEOTIDE-SEQUENCE OF THE GAG GENE AND GAG-POL JUNCTION OF FELINE LEUKEMIA-VIRUS
NUCLEOTIDE-SEQUENCE OF THE GAG GENE AND GAG-POL JUNCTION OF FELINE LEUKEMIA-VIRUS
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DOI：
10.1128/jvi.50.3.884-894.1984
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发表时间：
1984-01-01
影响因子：
5.4
通讯作者：
GALIBERT, F
中科院分区：
文献类型：
--
作者：
LAPREVOTTE, I;HAMPE, A;GALIBERT, F
测定了猫白血病病毒Gag基因及其侧翼序列，并与2株猫肉瘤病毒及小鼠白血病病毒Moloney株的相应序列进行了比较。猫白血病病毒与小鼠白血病病毒Gag基因的核苷酸序列具有高度的同源性，提示家猫和实验小鼠的逆转录病毒具有共同的近端进化前体。预测的猫白血病病毒Gag基因前体的完整结构表明，非糖化和糖基化的Gag基因多肽的翻译起始于两个不同的AUG密码子。这些启动子密码子落在相同的阅读框中，并被编码氨基末端信号肽的222个碱基对片段分开。核苷酸序列预测了每个单独的Gag编码蛋白(p15、p12、p30、p10)中的氨基酸顺序，所有这些蛋白质都来自Gag基因前体。针对病毒RNA的两个区域，提出了稳定的茎和环二级结构。第一个属于病毒基因组5‘端的序列，以及可能在RNA亚基的二聚体连接中发挥作用的相邻回文序列。第二个包括gag-pol连接处的编码序列，并被认为参与pol1基因产物的翻译。对后一个区域的序列分析表明，Gag和Pol1基因在不同的阅读框中翻译。经典的共同剪接供体和受体序列不能被定位到能够合成预期的Gag-Poll前体蛋白的区域。显然，Poll基因产物(RNA依赖的DNA聚合酶)可以通过移码抑制机制翻译，这可能涉及茎和环的切割修饰，其方式类似于tRNA加工中观察到的方式。
The nucleotide sequence of the gag gene of feline leukemia virus and its flanking sequences were determined and compared with the corresponding sequences of 2 strains of feline sarcoma virus and with that of the Moloney strain of murine leukemia virus. A high degree of nucleotide sequence homology between the feline leukemia virus and murine leukemia virus gag genes was observed, suggesting that retroviruses of domestic cats and laboratory mice have a common, proximal evolutionary progenitor. The predicted structure of the complete feline leukemia virus gag gene precursor suggests that the translation of nonglycosylated and glycosylated gag gene polypeptides is initiated at 2 different AUG codons. These initiator codons fall in the same reading frame and are separated by a 222-base-pair segment which encodes an amino terminal signal peptide. The nucleotide sequence predicts the order of amino acids in each of the individual gag-coded proteins (p15, p12, p30, p10), all of which derive from the gag gene precursor. Stable stem-and-loop secondary structures are proposed for two regions of viral RNA. The first falls within sequences at the 5'' end of the viral genome, together with adjacent palindromic sequences which may play a role in dimer linkage of RNA subunits. The second includes coding sequences at the gag-pol junction and is proposed to be involved in translation of the pol gene product. Sequence analysis of the latter region shows that the gag and pol genes are translated in different reading frames. Classical consensus splice donor and acceptor sequences could not be localized to regions which would permit synthesis of the expected gag-pol precursor protein. Evidently, the pol gene product (RNA-dependent DNA polymerase) could be translated by a frameshift suppressing mechanism which could involve cleavage modification of stems and loops in a manner similar to that observed in tRNA processing.