Godeny E K, Chen L, Kumar S N, Methven S L, Koonin E V, Brinton M A
Department of Biology, Georgia State University, Atlanta 30302.
Virology. 1993 Jun;194(2):585-96. doi: 10.1006/viro.1993.1298.
The apparently complete sequence of the RNA genome of the neurovirulent isolate of lactate dehydrogenase-elevating virus (LDV-C) has been determined. The LDV-C genome is at least 14,222 nucleotides in length and contains eight open reading frames (ORFs). ORF 1a, which encodes a protein of 242.8 kDa and is located at the 5' end of the genome, contains at least two putative papain-like cysteine protease domains, and one putative chymotrypsin-like serine protease domain. This ORF terminates with a UAG stop codon that can be bypassed if a -1 frameshift occurs. The frameshift region consists of a heptanucleotide "slippery" sequence, 5'-UUUAAAC-3', followed by a putative pseudoknot. ORF 1b encodes a protein of 155.4 kDa containing, in its N-terminal portion, an RNA-dependent RNA polymerase and an RNA helicase domain separated by a Zn finger domain. Another domain of unknown function that is also conserved in coronaviruses and toroviruses is located at the C-terminus of the ORF 1b product. Three cleavage sites in the ORF 1a polyprotein and three in the ORF 1b polyprotein were predicted for the chymotrypsin-like protease and tentatively delimit the mature nonstructural proteins of LDV. Six small, overlapping 3' ORFs (ORFs 2 through 7) encode proteins with calculated sizes of 25.8, 21.6, 19.8, 23.9, 18.9, and 12.3 kDa. ORF 7 encodes the virion nucleocapsid protein Vp-1, while ORF 6 encodes the nonglycosylated envelope protein Vp2. ORFs 5, 4, 3, and 2 each encode glycoproteins which may be virion envelope proteins. LDV is closely related to equine arteritis virus, Lelystad virus (LV), and simian hemorrhagic fever virus. These four viruses belong to a new group of positive-strand RNA viruses and are related to coronaviruses and toroviruses.
已确定乳酸脱氢酶升高病毒（LDV-C）神经毒力分离株RNA基因组的明显完整序列。LDV-C基因组长度至少为14222个核苷酸，包含八个开放阅读框（ORF）。ORF 1a位于基因组5'端，编码一个242.8 kDa的蛋白质，包含至少两个假定的木瓜蛋白酶样半胱氨酸蛋白酶结构域和一个假定的胰凝乳蛋白酶样丝氨酸蛋白酶结构域。该ORF以UAG终止密码子结束，如果发生-1移码则可以绕过。移码区域由一个七核苷酸“滑溜”序列5'-UUUAAAC-3'组成，后面跟着一个假定的假结。ORF 1b编码一个155.4 kDa的蛋白质，在其N端部分包含一个依赖RNA的RNA聚合酶和一个由锌指结构域隔开的RNA解旋酶结构域。另一个在冠状病毒和环曲病毒中也保守的未知功能结构域位于ORF 1b产物的C端。预测ORF 1a多聚蛋白中的三个切割位点和ORF 1b多聚蛋白中的三个切割位点为胰凝乳蛋白酶样蛋白酶，并初步界定了LDV的成熟非结构蛋白。六个小的重叠3' ORF（ORF 2至7）编码计算大小分别为25.8、21.6、19.8、23.9、18.9和12.3 kDa的蛋白质。ORF 7编码病毒粒子核衣壳蛋白Vp-1，而ORF 6编码非糖基化包膜蛋白Vp2。ORF 5、4、3和2各自编码可能是病毒粒子包膜蛋白的糖蛋白。LDV与马动脉炎病毒、莱利斯塔德病毒（LV）和猴出血热病毒密切相关。这四种病毒属于一组新的正链RNA病毒，与冠状病毒和环曲病毒有关。
