Pappu H R, Karasev A V, Anderson E J, Pappu S S, Hilf M E, Febres V J, Eckloff R M, McCaffery M, Boyko V, Gowda S
Plant Pathology Department, University of Florida, Gainesville 32611.
Virology. 1994 Feb 15;199(1):35-46. doi: 10.1006/viro.1994.1095.
The citrus tristeza closterovirus (CTV) RNA genome was cloned as cDNA generated from both CTV-specific double-stranded RNA and genomic RNA, and the sequence of the 3' 7292 nucleotides was determined. The sequenced portion contained eight open reading frames potentially encoding, in the 5' to 3' direction, proteins with the apparent molecular weights of 65, 61, 27, 25 (capsid protein, CP), 18, 13, 20, and 23 kDa, and a potential noncoding region of 277 nucleotides. The 65-kDa protein is a viral homolog of cellular hsp70 heat shock proteins (hsp), the 61-kDa protein is distantly related to the hsp90 proteins, and the 27-kDa protein is a diverged copy of the CP. Database searches did not identify any protein sequences of significant similarity to the remaining four ORFs downstream of the CP. A specific four-gene module consisting of the hsp70 protein, the hsp90-related protein, the diverged copy of the CP, and the CP itself was found to be common in organization between CTV and beet yellows closterovirus. All four proteins in this module were highly conserved, indicating that these viruses probably have evolved from a common ancestor.
柑橘衰退病毒（CTV）的RNA基因组是从CTV特异性双链RNA和基因组RNA生成的cDNA中克隆出来的，并测定了其3'端7292个核苷酸的序列。测序部分包含八个开放阅读框，从5'到3'方向潜在编码的蛋白质表观分子量分别为65、61、27、25（衣壳蛋白，CP）、18、13、20和23 kDa，还有一个277个核苷酸的潜在非编码区。65 kDa的蛋白质是细胞hsp70热休克蛋白（hsp）的病毒同源物，61 kDa的蛋白质与hsp90蛋白质有较远的亲缘关系，27 kDa的蛋白质是CP的一个分化拷贝。数据库搜索未发现与CP下游其余四个开放阅读框有显著相似性的任何蛋白质序列。发现由hsp70蛋白、hsp90相关蛋白、CP的分化拷贝和CP本身组成的一个特定四基因模块在CTV和甜菜黄化病毒的组织结构中是常见的。该模块中的所有四种蛋白质都高度保守，表明这些病毒可能起源于一个共同的祖先。
