3PQH

Crystal structure of the C-terminal fragment of the bacteriophage phi92 membrane-piercing protein gp138

Summary for 3PQH

• Entry DOI: 10.2210/pdb3pqh/pdb
• Related: 3PQI
• Descriptor: gene product 138, FE (III) ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: beta-helix, ob-fold, phage baseplate, iron-binding, cell membrane piercing, viral protein
• Biological source: Bacteriophage phi92
• Total number of polymer chains: 2
• Total formula weight: 26441.42

Authors

Browning, C.,Shneider, M.,Leiman, P.G. (deposition date: 2010-11-26, release date: 2012-02-22, Last modification date: 2024-02-21)

Primary citation

Browning, C.,Shneider, M.M.,Bowman, V.D.,Schwarzer, D.,Leiman, P.G.
Phage pierces the host cell membrane with the iron-loaded spike.
Structure, 20:326-339, 2012

PubMed Abstract: Bacteriophages with contractile tails and the bacterial type VI secretion system have been proposed to use a special protein to create an opening in the host cell membrane during infection. These proteins have a modular architecture but invariably contain an oligonucleotide/oligosaccharide-binding (OB-fold) domain and a long β-helical C-terminal domain, which initiates the contact with the host cell membrane. Using X-ray crystallography and electron microscopy, we report the atomic structure of the membrane-piercing proteins from bacteriophages P2 and ϕ92 and identify the residues that constitute the membrane-attacking apex. Both proteins form compact spikes with a ∼10Å diameter tip that is stabilized by a centrally positioned iron ion bound by six histidine residues. The accumulated data strongly suggest that, in the process of membrane penetration, the spikes are translocated through the lipid bilayer without undergoing major unfolding.

PubMed: 22325780
DOI: 10.1016/j.str.2011.12.009

Experimental method

X-RAY DIFFRACTION (1.295 Å)