Hahn C S, Hahn Y S, Rice C M, Lee E, Dalgarno L, Strauss E G, Strauss J H
Division of Biology, California Institute of Technology, Pasadena 91125.
J Mol Biol. 1987 Nov 5;198(1):33-41. doi: 10.1016/0022-2836(87)90455-4.
We have isolated a cDNA clone after reverse transcription of the genomic RNA of Asibi yellow fever virus whose structure suggests it was formed by self-priming from a 3'-terminal hairpin of 87 nucleotides in the genomic RNA. We have also isolated a clone from cDNA made to Murray Valley encephalitis virus RNA that also appears to have arisen by self-priming from a 3'-terminal structure very similar or identical to that of yellow fever. In addition, 3'-terminal sequencing of the S1 strain of dengue 2 RNA shows that this RNA is also capable of forming a 3'-terminal hairpin of 79 nucleotides. Furthermore, we have identified two 20-nucleotide sequence elements which are present in the 3' untranslated region of all three viruses; one of these sequence elements is repeated in Murray Valley encephalitis and dengue 2 RNA but not in yellow fever RNA. In all three viruses, which represent the three major serological subgroups of the mosquito-borne flaviviruses, the 3'-proximal conserved sequence element, which is found immediately adjacent to the potential 3'-terminal hairpin, is complementary to another conserved domain near the 5' end of the viral RNAs, suggesting that flavivirus RNAs can cyclize (calculated delta G less than -11 kcal; 1 kcal = 4.184 kJ).
我们通过逆转录阿西比黄热病病毒的基因组RNA分离出了一个cDNA克隆，其结构表明它是由基因组RNA中一个87个核苷酸的3'末端发夹自引发形成的。我们还从针对墨累谷脑炎病毒RNA制备的cDNA中分离出了一个克隆，该克隆似乎也是通过与黄热病病毒非常相似或相同的3'末端结构自引发产生的。此外，登革2型RNA的S1株的3'末端测序表明，这种RNA也能够形成一个79个核苷酸的3'末端发夹。此外，我们还鉴定出了两个20个核苷酸的序列元件，它们存在于所有这三种病毒的3'非翻译区；其中一个序列元件在墨累谷脑炎病毒和登革2型RNA中重复出现，但在黄热病病毒RNA中没有。在代表蚊媒黄病毒三个主要血清学亚组的所有这三种病毒中，紧邻潜在3'末端发夹的3'近端保守序列元件与病毒RNA 5'末端附近的另一个保守结构域互补，这表明黄病毒RNA可以环化（计算得出的ΔG小于-11千卡；1千卡 = 4.184千焦）。
