Russell R L, Funk C J, Rohrmann G F
Department of Agricultural Chemistry, Oregon State University, Corvallis, Oregon, 97331-7301, USA.
Virology. 1997 Jan 6;227(1):142-52. doi: 10.1006/viro.1996.8304.
An open reading frame homologous to AcMNPV ORF9 (ORF1629) was characterized in the Orgyia pseudotsugata multinucleocapsid nuclear polyhedrosis virus (OpMNPV). Sequence analysis indicated that the OpMNPV homolog (called ORF2) encoded a protein predicted to contain 545 amino acids with a molecular weight of 61 kDa. The first 80 amino acids did not have a counterpart in the AcMNPV homolog. The remainder of the ORF was poorly conserved with 29% amino acid identity overall with the AcMNPV ORF. However, the amino terminal 150 amino acids of AcMNPV ORF9 demonstrated about 45% amino acid sequence identity with OpMNPV ORF2 and conserved runs of proline residues were present in internal regions of both molecules. Transcriptional mapping indicated the ORF2 transcripts were initiated at a late promoter sequence, ATAAG, beginning about 24 hr p.i. These transcripts terminated near the 3' end of the ORF2 reading frame. Antibodies were produced against a fusion protein derived from the bacterial gene encoding the maltose binding protein and most of the ORF2 sequence. These antibodies reacted with a protein of 69 kDa on Western blots and the protein was found to be associated with virions isolated from both polyhedra and budded virus. The OpMNPV ORF2 antiserum also reacted with the AcMNPV ORF9 gene product. Immunoelectron microscopic analyses indicated that ORF2 was associated with the ends of the capsids which contain the basal structure. This end appears to be oriented away from both the virogenic stroma and membranes involved in intranuclear envelopment. In addition, as virions bud from the nucleus into the cytoplasm, this end also appears to be oriented away from the nuclear membrane.
在云杉毒蛾多核衣壳核型多角体病毒（OpMNPV）中鉴定出了一个与苜蓿银纹夜蛾核型多角体病毒（AcMNPV）ORF9（ORF1629）同源的开放阅读框。序列分析表明，OpMNPV同源物（称为ORF2）编码一种预测含有545个氨基酸、分子量为61 kDa的蛋白质。前80个氨基酸在AcMNPV同源物中没有对应物。ORF的其余部分保守性较差，与AcMNPV ORF的总体氨基酸同一性为29%。然而，AcMNPV ORF9的氨基末端150个氨基酸与OpMNPV ORF2表现出约45%的氨基酸序列同一性，并且在两个分子的内部区域都存在保守的脯氨酸残基序列。转录图谱显示，ORF2转录本从一个晚期启动子序列ATAAG开始，在感染后约24小时开始。这些转录本在ORF2阅读框的3'端附近终止。针对源自编码麦芽糖结合蛋白的细菌基因和大部分ORF2序列的融合蛋白产生了抗体。这些抗体在蛋白质印迹上与一种69 kDa的蛋白质发生反应，并且发现该蛋白质与从多角体和出芽病毒中分离出的病毒粒子相关。OpMNPV ORF2抗血清也与AcMNPV ORF9基因产物发生反应。免疫电子显微镜分析表明，ORF2与含有基部结构的衣壳末端相关。这个末端似乎远离病毒发生基质和参与核内包囊的膜。此外，当病毒粒子从细胞核出芽进入细胞质时，这个末端似乎也远离核膜。
