3J7V

Capsid Expansion Mechanism Of Bacteriophage T7 Revealed By Multi-State Atomic Models Derived From Cryo-EM Reconstructions

3J7V の概要

• エントリーDOI: 10.2210/pdb3j7v/pdb
• 関連するPDBエントリー: 3J7W 3J7X
• EMDBエントリー: 6034 6035 6036 6037
• 分子名称: Major capsid protein 10A (1 entity in total)
• 機能のキーワード: maturation, dna packaging, procapsid, non-covalent topological linking, virus
• 由来する生物種: Enterobacteria phage T7
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 256127.38

構造登録者

Guo, F.,Liu, Z.,Fang, P.A.,Zhang, Q.,Wright, E.T.,Wu, W.,Zhang, C.,Vago, F.,Ren, Y.,Jakata, J.,Chiu, W.,Serwer, P.,Jiang, W. (登録日: 2014-08-12, 公開日: 2014-10-15, 最終更新日: 2024-02-21)

主引用文献

Guo, F.,Liu, Z.,Fang, P.A.,Zhang, Q.,Wright, E.T.,Wu, W.,Zhang, C.,Vago, F.,Ren, Y.,Jakana, J.,Chiu, W.,Serwer, P.,Jiang, W.
Capsid expansion mechanism of bacteriophage T7 revealed by multistate atomic models derived from cryo-EM reconstructions.
Proc.Natl.Acad.Sci.USA, 111:E4606-E4614, 2014

PubMed Abstract: Many dsDNA viruses first assemble a DNA-free procapsid, using a scaffolding protein-dependent process. The procapsid, then, undergoes dramatic conformational maturation while packaging DNA. For bacteriophage T7 we report the following four single-particle cryo-EM 3D reconstructions and the derived atomic models: procapsid (4.6-Å resolution), an early-stage DNA packaging intermediate (3.5 Å), a later-stage packaging intermediate (6.6 Å), and the final infectious phage (3.6 Å). In the procapsid, the N terminus of the major capsid protein, gp10, has a six-turn helix at the inner surface of the shell, where each skewed hexamer of gp10 interacts with two scaffolding proteins. With the exit of scaffolding proteins during maturation the gp10 N-terminal helix unfolds and swings through the capsid shell to the outer surface. The refolded N-terminal region has a hairpin that forms a novel noncovalent, joint-like, intercapsomeric interaction with a pocket formed during shell expansion. These large conformational changes also result in a new noncovalent, intracapsomeric topological linking. Both interactions further stabilize the capsids by interlocking all pentameric and hexameric capsomeres in both DNA packaging intermediate and phage. Although the final phage shell has nearly identical structure to the shell of the DNA-free intermediate, surprisingly we found that the icosahedral faces of the phage are slightly (∼4 Å) contracted relative to the faces of the intermediate, despite the internal pressure from the densely packaged DNA genome. These structures provide a basis for understanding the capsid maturation process during DNA packaging that is essential for large numbers of dsDNA viruses.

PubMed: 25313071
DOI: 10.1073/pnas.1407020111

実験手法

ELECTRON MICROSCOPY (4.6 Å)