VISUALIZATION AND CHARACTERIZATION OF TOBACCO MOSAIC-VIRUS MOVEMENT PROTEIN-BINDING TO SINGLE-STRANDED NUCLEIC-ACIDS
VISUALIZATION AND CHARACTERIZATION OF TOBACCO MOSAIC-VIRUS MOVEMENT PROTEIN-BINDING TO SINGLE-STRANDED NUCLEIC-ACIDS
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DOI：
10.1105/tpc.4.4.397
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发表时间：
1992-04-01
期刊：
影响因子：
11.6
通讯作者：
ZAMBRYSKI, P
中科院分区：
文献类型：
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作者：
CITOVSKY, V;WONG, ML;ZAMBRYSKI, P
烟草花叶病毒（TMV）的细胞间传播被认为是通过植物细胞间的连接，即胞间连丝进行的。 病毒运动是由病毒编码的P30蛋白介导的主动过程。 P30具有至少两种功能，即协同结合单链核酸和增加胞间连丝渗透性。 在这里，我们可视化了P30与单链DNA和RNA的复合物。 这些复合物是长的，未折叠的，并且非常薄（直径为1.5至2.0 nm）。 与TMV病毒粒子（300 × 18 nm）不同，复合物的大小与P30诱导的胞间连丝通透性增加（2.4 - 3.1 nm）相容，使其成为TMV细胞间运动所涉及结构的可能候选者。 使用P30的单缺失和双缺失突变体的突变分析揭示了对蛋白质功能潜在重要的三个区域。 氨基酸残基65至86可能是活性蛋白正确折叠所需的，氨基酸残基112至185和185至268之间的区域可能含有两个独立活性的单链核酸结合结构域，分别称为结合结构域A和B。
Cell-to-cell spread of tobacco mosaic virus (TMV) is presumed to occur through plant intercellular connections, the plasmodesmata. Viral movement is an active process mediated by a specific virus-encoded P30 protein. P30 has at least two functions, to cooperatively bind single-stranded nucleic acids and to increase plasmodesmatal permeability. Here, we visualized P30 complexes with single-stranded DNA and RNA. These complexes are long, unfolded, and very thin (1.5 to 2.0 nm in diameter). Unlike TMV virions (300 x 18 nm), the complexes are compatible in size with the P30-induced increase in plasmodesmatal permeability (2.4 to 3.1 nm), making them likely candidates for the structures involved in the cell-to-cell movement of TMV. Mutational analysis using single and double deletion mutants of P30 revealed three regions potentially important for the protein function. Amino acid residues 65 to 86 possibly are required for correct folding of the active protein, and the regions between amino acid residues 112 to 185 and 185 to 268 potentially contain two independently active single-stranded nucleic acid binding domains designated binding domains A and B, respectively.