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Cryo-EM structure of the bacteriophage T4 portal protein assembly at near-atomic resolution.

Sun L, Zhang X, Gao S, Rao PA, Padilla-Sanchez V, Chen Z, Sun S, Xiang Y, Subramaniam S, Rao VB, Rossmann MG - Nat Commun (2015)

Bottom Line: However, the detailed structure of the portal protein remained unknown.The gp20 structure also verifies that the portal assembly is required for initiating head assembly, for attachment of the packaging motor, and for participation in DNA packaging.Comparison of the Myoviridae T4 portal structure with the known portal structures of φ29, SPP1 and P22, representing Podo- and Siphoviridae, shows that the portal structure probably dates back to a time when self-replicating microorganisms were being established on Earth.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Purdue University, 240S. Martin Jischke Drive, West Lafayette, Indiana 47907-2032, USA.

ABSTRACT
The structure and assembly of bacteriophage T4 has been extensively studied. However, the detailed structure of the portal protein remained unknown. Here we report the structure of the bacteriophage T4 portal assembly, gene product 20 (gp20), determined by cryo-electron microscopy (cryo-EM) to 3.6 Å resolution. In addition, analysis of a 10 Å resolution cryo-EM map of an empty prolate T4 head shows how the dodecameric portal assembly interacts with the capsid protein gp23 at the special pentameric vertex. The gp20 structure also verifies that the portal assembly is required for initiating head assembly, for attachment of the packaging motor, and for participation in DNA packaging. Comparison of the Myoviridae T4 portal structure with the known portal structures of φ29, SPP1 and P22, representing Podo- and Siphoviridae, shows that the portal structure probably dates back to a time when self-replicating microorganisms were being established on Earth.

No MeSH data available.


Related in: MedlinePlus

Left and centre: possible rooted phylogenetic trees (tree 1 and tree 2) that might represent the evolution of the primordial portal protein R to the current portal proteins of bacteriophages (a–d).The lengths of the branches are labelled as (a,b,d–f). The tree on the right shows the tree that best fitted the structural observations.
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f7: Left and centre: possible rooted phylogenetic trees (tree 1 and tree 2) that might represent the evolution of the primordial portal protein R to the current portal proteins of bacteriophages (a–d).The lengths of the branches are labelled as (a,b,d–f). The tree on the right shows the tree that best fitted the structural observations.

Mentions: There are two types of rooted, phylogenetic trees (‘tree 1' and ‘tree 2') that can be drawn for the evolution of four known structures each with seven parameters defining the lengths of the branches of the trees (Fig. 7). There are 12 different ways of arranging the four structures at the end of the branches furthest from the root. However, tree 1 has symmetry allowing for only three unique tree varieties. Hence, in total, there are three varieties of tree 1 and twelve varieties of tree 2.


Cryo-EM structure of the bacteriophage T4 portal protein assembly at near-atomic resolution.

Sun L, Zhang X, Gao S, Rao PA, Padilla-Sanchez V, Chen Z, Sun S, Xiang Y, Subramaniam S, Rao VB, Rossmann MG - Nat Commun (2015)

Left and centre: possible rooted phylogenetic trees (tree 1 and tree 2) that might represent the evolution of the primordial portal protein R to the current portal proteins of bacteriophages (a–d).The lengths of the branches are labelled as (a,b,d–f). The tree on the right shows the tree that best fitted the structural observations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493910&req=5

f7: Left and centre: possible rooted phylogenetic trees (tree 1 and tree 2) that might represent the evolution of the primordial portal protein R to the current portal proteins of bacteriophages (a–d).The lengths of the branches are labelled as (a,b,d–f). The tree on the right shows the tree that best fitted the structural observations.
Mentions: There are two types of rooted, phylogenetic trees (‘tree 1' and ‘tree 2') that can be drawn for the evolution of four known structures each with seven parameters defining the lengths of the branches of the trees (Fig. 7). There are 12 different ways of arranging the four structures at the end of the branches furthest from the root. However, tree 1 has symmetry allowing for only three unique tree varieties. Hence, in total, there are three varieties of tree 1 and twelve varieties of tree 2.

Bottom Line: However, the detailed structure of the portal protein remained unknown.The gp20 structure also verifies that the portal assembly is required for initiating head assembly, for attachment of the packaging motor, and for participation in DNA packaging.Comparison of the Myoviridae T4 portal structure with the known portal structures of φ29, SPP1 and P22, representing Podo- and Siphoviridae, shows that the portal structure probably dates back to a time when self-replicating microorganisms were being established on Earth.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Purdue University, 240S. Martin Jischke Drive, West Lafayette, Indiana 47907-2032, USA.

ABSTRACT
The structure and assembly of bacteriophage T4 has been extensively studied. However, the detailed structure of the portal protein remained unknown. Here we report the structure of the bacteriophage T4 portal assembly, gene product 20 (gp20), determined by cryo-electron microscopy (cryo-EM) to 3.6 Å resolution. In addition, analysis of a 10 Å resolution cryo-EM map of an empty prolate T4 head shows how the dodecameric portal assembly interacts with the capsid protein gp23 at the special pentameric vertex. The gp20 structure also verifies that the portal assembly is required for initiating head assembly, for attachment of the packaging motor, and for participation in DNA packaging. Comparison of the Myoviridae T4 portal structure with the known portal structures of φ29, SPP1 and P22, representing Podo- and Siphoviridae, shows that the portal structure probably dates back to a time when self-replicating microorganisms were being established on Earth.

No MeSH data available.


Related in: MedlinePlus