4OSD

Dimer of a C-terminal fragment of phage T4 gp5 beta-helix

Summary for 4OSD

• Entry DOI: 10.2210/pdb4osd/pdb
• Related: 1K28 4JJ2
• Descriptor: Tail-associated lysozyme, 9-OCTADECENOIC ACID, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: membrane piercing, t4 gp5, triple beta-helix, sds resistant, donor strand exchange, fragment, membrane piercing complex, gp5.4, gp27-gp5 complex, hydrolase
• Biological source: Enterobacteria phage T4
• Cellular location: Virion : P16009
• Total number of polymer chains: 18
• Total formula weight: 181505.33

Authors

Buth, S.A.,Leiman, P.G.,Shneider, M.M. (deposition date: 2014-02-12, release date: 2015-02-18, Last modification date: 2023-11-08)

Primary citation

Buth, S.A.,Menin, L.,Shneider, M.M.,Engel, J.,Boudko, S.P.,Leiman, P.G.
Structure and Biophysical Properties of a Triple-Stranded Beta-Helix Comprising the Central Spike of Bacteriophage T4.
Viruses, 7:4676-4706, 2015

PubMed Abstract: Gene product 5 (gp5) of bacteriophage T4 is a spike-shaped protein that functions to disrupt the membrane of the target cell during phage infection. Its C-terminal domain is a long and slender β-helix that is formed by three polypeptide chains wrapped around a common symmetry axis akin to three interdigitated corkscrews. The folding and biophysical properties of such triple-stranded β-helices, which are topologically related to amyloid fibers, represent an unsolved biophysical problem. Here, we report structural and biophysical characterization of T4 gp5 β-helix and its truncated mutants of different lengths. A soluble fragment that forms a dimer of trimers and that could comprise a minimal self-folding unit has been identified. Surprisingly, the hydrophobic core of the β-helix is small. It is located near the C-terminal end of the β-helix and contains a centrally positioned and hydrated magnesium ion. A large part of the β-helix interior comprises a large elongated cavity that binds palmitic, stearic, and oleic acids in an extended conformation suggesting that these molecules might participate in the folding of the complete β-helix.

PubMed: 26295253
DOI: 10.3390/v7082839

Experimental method

X-RAY DIFFRACTION (1.96 Å)