Koenig R, Pleij C W A, Loss S, Burgermeister W, Aust H, Schiemann J
Biologische Bundesanstalt für Land- und Forstwirtschaft, Institut für Pflanzenvirologie, Mikrobiologie und biologische Sicherheit, Braunschweig, Germany.
Arch Virol. 2004 May;149(5):903-14. doi: 10.1007/s00705-003-0268-5. Epub 2004 Jan 29.
The genome properties of three potexviruses which previously had been isolated from different genera in the family Cactaceae and had been found to be only distantly related serologically have been studied. The sequence of the 3040 3' terminal nucleotides of the genomic RNA of isolate K11 from Schlumbergera bridgesii and the complete RNA sequences of isolates B1 and CC10 from Zygocactus sp. and Opuntia sp., respectively, were determined. Starting sequences were obtained by means of immunocapture reverse transcription PCR using primers derived from highly conserved sequences in other potexviral RNAs. The known parts of the sequences were extended by means of random-primed cDNAs and specific primers derived from the known parts of the sequences. The genome structure of the three viruses resembles that of other potexviruses. The conserved motifs typical for replication-associated proteins, triple gene block (TGB) proteins and coat proteins of potexviruses were readily identified in the translation products of the five open reading frames. The 3' untranslated regions of the three RNAs are folded into secondary structures containing three characteristic hairpins. Rather low percentages of amino acid sequence identities ranging from 62% to 76% for the coat proteins and 41% to 49% for TGB proteins 3 suggest that these viruses should be regarded as distinct virus species for which the names Zygocactus virus X, Schlumbergera virus X and Opuntia virus X are proposed. It is also suggested that the name Cactus virus X which originally was coined for all three virus isolates should no longer be used.
对三种马铃薯X病毒的基因组特性进行了研究，这三种病毒先前从仙人掌科不同属中分离得到，血清学上仅发现有远缘关系。分别测定了来自蟹爪兰的分离株K11基因组RNA 3'末端3040个核苷酸的序列，以及来自蟹爪兰属和仙人掌属的分离株B1和CC10的完整RNA序列。起始序列通过免疫捕获逆转录PCR获得，所用引物来源于其他马铃薯X病毒RNA中的高度保守序列。已知的序列部分通过随机引物cDNA和来源于已知序列部分的特异性引物进行延伸。这三种病毒的基因组结构与其他马铃薯X病毒相似。在五个开放阅读框的翻译产物中很容易鉴定出马铃薯X病毒复制相关蛋白、三基因块（TGB）蛋白和外壳蛋白典型的保守基序。三种RNA的3'非翻译区折叠成含有三个特征性发夹结构的二级结构。外壳蛋白的氨基酸序列同一性百分率相当低，为62%至76%，TGB蛋白3的氨基酸序列同一性百分率为41%至49%，这表明这些病毒应被视为不同的病毒种，为此提出了蟹爪兰X病毒、蟹爪莲X病毒和仙人掌X病毒的名称。还建议不再使用最初为所有三种病毒分离株创造的仙人掌X病毒这一名称。
