Argüello-Astorga G R, Guevara-González R G, Herrera-Estrella L R, Rivera-Bustamante R F
Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato, Guanajuato, Mexico.
Virology. 1994 Aug 15;203(1):90-100. doi: 10.1006/viro.1994.1458.
A phylogenetic and structural analysis of the intergenic region of 22 dicot-infecting and 8 monocot-infecting geminiviruses was carried out. The analysis allowed the identification of iterative sequence motifs 8-12 nucleotides in length, whose organization (number, orientation, and spacing) is highly conserved within each of the three major lineages of dicot-geminiviruses, according to the phylogeny derived from the amino acid sequences of the replication-associated protein (AL1). The iterated elements differ in sequence even between closely related viruses, and are found in the vicinity of the putative TATA box of the AL1 gene in all dicot-infecting geminiviruses. Analogous elements were identified also in monocot-infecting geminiviruses, but the arrangement was different, since one of the iterative sequences is part of the conserved hairpin structure essential for replication of all the members of this viral family. We propose here that the iterated sequences are the specific binding sites of the geminiviral replication-associated proteins and show that the hypothesis is in agreement with the experimental data available to date. Additionally, a model of geminivirus replication that involves the participation of host transcription factors in the process is presented.
对22种双子叶植物感染型双生病毒和8种单子叶植物感染型双生病毒的基因间隔区进行了系统发育和结构分析。该分析能够鉴定出长度为8 - 12个核苷酸的重复序列基序，根据复制相关蛋白（AL1）氨基酸序列推导的系统发育关系，其组织形式（数量、方向和间距）在双子叶植物双生病毒的三个主要谱系中各自高度保守。即使在亲缘关系很近的病毒之间，重复元件的序列也有所不同，并且在所有双子叶植物感染型双生病毒的AL1基因推定TATA框附近都能找到。在单子叶植物感染型双生病毒中也鉴定出了类似元件，但排列方式不同，因为其中一个重复序列是该病毒家族所有成员复制所必需的保守发夹结构的一部分。我们在此提出，这些重复序列是双生病毒复制相关蛋白的特异性结合位点，并表明该假设与目前可用的实验数据一致。此外，还提出了一个双生病毒复制模型，该模型涉及宿主转录因子参与这一过程。
