Conservation of the capsid structure in tailed dsDNA bacteriophages:: the pseudoatomic structure of φ29
Conservation of the capsid structure in tailed dsDNA bacteriophages:: the pseudoatomic structure of φ29
复制标题
DOI：
10.1016/j.molcel.2005.03.013
复制
发表时间：
2005-04-15
期刊：
影响因子：
16
通讯作者：
Rossmann, MG
中科院分区：
文献类型：
--
作者：
Morais, MC;Choi, KH;Rossmann, MG
噬菌体 phi 29 是已知最小、最简单的 dsDNA 噬菌体之一，使其适合结构研究。无纤维等距变体的三维结构已通过冷冻电子显微镜 (cryo-EM) 确定为 7.9 埃分辨率，从而可以识别螺旋和 β 片层。它们的排列表明，除了 phi 29 蛋白的额外免疫球蛋白样结构域外，phi 29 和噬菌体 HK97 衣壳蛋白的折叠相似。包含这两个域的原子模型非常适合 T = 3、无纤维等距 phi 29 粒子的冷冻电镜密度，以及纤维等距和无纤维 Prolate Prohead 029 粒子的冷冻电镜结构，分辨率分别为 8.7 埃和 12.7 埃。因此，phi 29 加入了越来越多利用 HK97 衣壳结构的噬菌体，这表明这种蛋白质折叠可能在 dsDNA 噬菌体的衣壳中普遍存在，就像果冻卷折叠在真核病毒中一样普遍。
Bacteriophage phi 29 is one of the smallest and simplest known dsDNA phages, making it amenable to structural investigations. The three-dimensional structure of a fiberless, isometric variant has been determined to 7.9 angstrom resolution by cryo-electron microscopy (cryo-EM), allowing the identification of a helices and beta sheets. Their arrangement indicates that the folds of the phi 29 and bacteriophage HK97 capsid proteins are similar except for an additional immunoglobulin-like domain of the phi 29 protein. An atomic model that incorporates these two domains fits well into the cryo-EM density of the T = 3, fiberless isometric phi 29 particle, and cryo-EM structures of fibered isometric and fiberless prolate prohead 029 particles at resolutions of 8.7 angstrom and 12.7 angstrom, respectively. Thus, phi 29 joins the growing number of phages that utilize the HK97 capsid structure, suggesting that this protein fold may be as prevalent in capsids of dsDNA phages as the jelly roll fold is in eukaryotic viruses.