2OM3

High-resolution cryo-EM structure of Tobacco Mosaic Virus

2OM3 の概要

• エントリーDOI: 10.2210/pdb2om3/pdb
• 関連するPDBエントリー: 1ei7 2tmv
• EMDBエントリー: 1316
• 分子名称: Tobacco Mosaic Virus RNA, Coat protein (2 entities in total)
• 機能のキーワード: protein-rna complex, four-helical up-and-down bundle, helical virus, virus
• 由来する生物種: Tobacco mosaic virus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 18464.09

構造登録者

Sachse, C. (登録日: 2007-01-20, 公開日: 2007-10-16, 最終更新日: 2023-12-27)

主引用文献

Sachse, C.,Chen, J.Z.,Coureux, P.D.,Stroupe, M.E.,Fandrich, M.,Grigorieff, N.
High-resolution electron microscopy of helical specimens: a fresh look at tobacco mosaic virus.
J.Mol.Biol., 371:812-835, 2007

PubMed Abstract: The treatment of helical objects as a string of single particles has become an established technique to resolve their three-dimensional (3D) structure using electron cryo-microscopy. It can be applied to a wide range of helical particles such as viruses, microtubules and helical filaments. We have made improvements to this approach using Tobacco Mosaic Virus (TMV) as a test specimen and obtained a map from 210,000 asymmetric units at a resolution better than 5 A. This was made possible by performing a full correction of the contrast transfer function of the microscope. Alignment of helical segments was helped by constraints derived from the helical symmetry of the virus. Furthermore, symmetrization was implemented by multiple inclusions of symmetry-related views in the 3D reconstruction. We used the density map to build an atomic model of TMV. The model was refined using a real-space refinement strategy that accommodates multiple conformers. The atomic model shows significant deviations from the deposited model for the helical form of TMV at the lower-radius region (residues 88 to 109). This region appears more ordered with well-defined secondary structure, compared with the earlier helical structure. The RNA phosphate backbone is sandwiched between two arginine side-chains, stabilizing the interaction between RNA and coat protein. A cluster of two or three carboxylates is buried in a hydrophobic environment isolating it from neighboring subunits. These carboxylates may represent the so-called Caspar carboxylates that form a metastable switch for viral disassembly. Overall, the observed differences suggest that the new model represents a different, more stable state of the virus, compared with the earlier published model.

PubMed: 17585939
DOI: 10.1016/j.jmb.2007.05.088

実験手法

ELECTRON MICROSCOPY (4.4 Å)