Structure and Biophysical Properties of a Triple-Stranded Beta-Helix Comprising the Central Spike of Bacteriophage T4.

Autor: Buth SA; Institute of Physics of Biological Systems, École Polytechnique Fédérale de Lausanne (EPFL), BSP 415, 1015 Lausanne, Switzerland. sergii.buth@epfl.ch., Menin L; Service de Spectrométrie de Masse, ISIC, EPFL, BCH 1520, 1015 Lausanne, Switzerland. laure.menin@epfl.ch., Shneider MM; Institute of Physics of Biological Systems, École Polytechnique Fédérale de Lausanne (EPFL), BSP 415, 1015 Lausanne, Switzerland. mm_shn@mail.ru.; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Laboratory of Molecular Bioengineering, 16/10 Miklukho-Maklaya St., 117997 Moscow, Russia. mm_shn@mail.ru., Engel J; Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland. juergen.engel@unibas.ch., Boudko SP; Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland. spb@shcc.org.; Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA. spb@shcc.org.; The Research Department, Shriner's Hospital for Children, 3101 Sam Jackson Park Road, Portland, OR 97239, USA. spb@shcc.org.; Department of Biochemistry and Molecular Biology, Oregon Health and Science University, 3181 Sam Jackson Park Road, Portland, OR 97239, USA. spb@shcc.org., Leiman PG; Institute of Physics of Biological Systems, École Polytechnique Fédérale de Lausanne (EPFL), BSP 415, 1015 Lausanne, Switzerland. petr.leiman@epfl.ch.; Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA. petr.leiman@epfl.ch.
Jazyk: angličtina
Zdroj: Viruses [Viruses] 2015 Aug 18; Vol. 7 (8), pp. 4676-706. Date of Electronic Publication: 2015 Aug 18.
DOI: 10.3390/v7082839
Abstrakt: 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.
Databáze: MEDLINE
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