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4jj2

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High resolution structure of a C-terminal fragment of the T4 phage gp5 beta-helix

Structural highlights

4jj2 is a 3 chain structure with sequence from Escherichia virus T4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.28Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NEEDL_BPT4 Tail-associated lysozyme of the baseplate hub that is essential for localized hydrolysis of bacterial cell wall necessary for viral DNA injection. The needle-like gp5 protein punctures the outer cell membrane and then digests the peptidoglycan cell wall in the periplasmic space. Involved in the tail assembly.^[1] ^[2]

Publication Abstract from PubMed

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 beta-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 beta-helices, which are topologically related to amyloid fibers, represent an unsolved biophysical problem. Here, we report structural and biophysical characterization of T4 gp5 beta-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 beta-helix is small. It is located near the C-terminal end of the beta-helix and contains a centrally positioned and hydrated magnesium ion. A large part of the beta-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 beta-helix.

Structure and Biophysical Properties of a Triple-Stranded Beta-Helix Comprising the Central Spike of Bacteriophage T4.,Buth SA, Menin L, Shneider MM, Engel J, Boudko SP, Leiman PG Viruses. 2015 Aug 18;7(8):4676-706. doi: 10.3390/v7082839. PMID:26295253^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Weigele PR, Scanlon E, King J. Homotrimeric, beta-stranded viral adhesins and tail proteins. J Bacteriol. 2003 Jul;185(14):4022-30. PMID:12837775
↑ Leiman PG, Arisaka F, van Raaij MJ, Kostyuchenko VA, Aksyuk AA, Kanamaru S, Rossmann MG. Morphogenesis of the T4 tail and tail fibers. Virol J. 2010 Dec 3;7:355. doi: 10.1186/1743-422X-7-355. PMID:21129200 doi:10.1186/1743-422X-7-355
↑ Buth SA, Menin L, Shneider MM, Engel J, Boudko SP, Leiman PG. Structure and Biophysical Properties of a Triple-Stranded Beta-Helix Comprising the Central Spike of Bacteriophage T4. Viruses. 2015 Aug 18;7(8):4676-706. PMID:26295253 doi:10.3390/v7082839