EMD-8661

Single-particle
3.3 Å
EMD-8661 Deposition: 06/04/2017
Map released: 13/09/2017
Last modified: 13/03/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-8661

Cryo-EM reconstruction of the bacteriophage T4 isometric capsid

EMD-8661

Single-particle
3.3 Å
EMD-8661 Deposition: 06/04/2017
Map released: 13/09/2017
Last modified: 13/03/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Enterobacteria phage T4
Sample: Enterobacteria phage T4
Fitted models: 5vf3 (Avg. Q-score: 0.505)

Deposition Authors: Chen Z, Sun L
Cryo-EM structure of the bacteriophage T4 isometric head at 3.3- angstrom resolution and its relevance to the assembly of icosahedral viruses.
Chen Z, Sun L, Zhang Z, Fokine A, Padilla-Sanchez V , Hanein D, Jiang W, Rossmann MG, Rao VB
(2017) PNAS , 114 , E8184 - E8193
PUBMED: 28893988
DOI: doi:10.1073/pnas.1708483114
ISSN: 1091-6490
ASTM: PNASA6
Abstract:
The 3.3-Å cryo-EM structure of the 860-Å-diameter isometric mutant bacteriophage T4 capsid has been determined. WT T4 has a prolate capsid characterized by triangulation numbers (T numbers) Tend = 13 for end caps and Tmid = 20 for midsection. A mutation in the major capsid protein, gp23, produced T=13 icosahedral capsids. The capsid is stabilized by 660 copies of the outer capsid protein, Soc, which clamp adjacent gp23 hexamers. The occupancies of Soc molecules are proportional to the size of the angle between the planes of adjacent hexameric capsomers. The angle between adjacent hexameric capsomers is greatest around the fivefold vertices, where there is the largest deviation from a planar hexagonal array. Thus, the Soc molecules reinforce the structure where there is the greatest strain in the gp23 hexagonal lattice. Mutations that change the angles between adjacent capsomers affect the positions of the pentameric vertices, resulting in different triangulation numbers in bacteriophage T4. The analysis of the T4 mutant head assembly gives guidance to how other icosahedral viruses reproducibly assemble into capsids with a predetermined T number, although the influence of scaffolding proteins is also important.