6QXM

Cryo-EM structure of T7 bacteriophage portal protein, 12mer, open valve

Summary for 6QXM

• Entry DOI: 10.2210/pdb6qxm/pdb
• Related: 6QWP 6QX5 6R21
• EMDB information: 4667 4669 4706
• Descriptor: Portal protein (1 entity in total)
• Functional Keywords: viral protein, dna packaging
• Biological source: Enterobacteria phage T7
• Total number of polymer chains: 12
• Total formula weight: 725500.64

Authors

Fabrega-Ferrer, M.,Cuervo, A.,Machon, C.,Fernandez, F.J.,Perez-Luque, R.,Pous, J.,Vega, M.C.,Carrascosa, J.L.,Coll, M. (deposition date: 2019-03-07, release date: 2019-09-04, Last modification date: 2024-05-15)

Primary citation

Cuervo, A.,Fabrega-Ferrer, M.,Machon, C.,Conesa, J.J.,Fernandez, F.J.,Perez-Luque, R.,Perez-Ruiz, M.,Pous, J.,Vega, M.C.,Carrascosa, J.L.,Coll, M.
Structures of T7 bacteriophage portal and tail suggest a viral DNA retention and ejection mechanism.
Nat Commun, 10:3746-3746, 2019

PubMed Abstract: Double-stranded DNA bacteriophages package their genome at high pressure inside a procapsid through the portal, an oligomeric ring protein located at a unique capsid vertex. Once the DNA has been packaged, the tail components assemble on the portal to render the mature infective virion. The tail tightly seals the ejection conduit until infection, when its interaction with the host membrane triggers the opening of the channel and the viral genome is delivered to the host cell. Using high-resolution cryo-electron microscopy and X-ray crystallography, here we describe various structures of the T7 bacteriophage portal and fiber-less tail complex, which suggest a possible mechanism for DNA retention and ejection: a portal closed conformation temporarily retains the genome before the tail is assembled, whereas an open portal is found in the tail. Moreover, a fold including a seven-bladed β-propeller domain is described for the nozzle tail protein.

PubMed: 31431626
DOI: 10.1038/s41467-019-11705-9

Experimental method

ELECTRON MICROSCOPY (4.1 Å)