4XYP

Crystal structure of a piscine viral fusion protein

Summary for 4XYP

• Entry DOI: 10.2210/pdb4xyp/pdb
• Descriptor: Fusion protein, 3,7-BIS(DIMETHYLAMINO)PHENOTHIAZIN-5-IUM, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: heptad repeat, 6-helix bundle, class i viral fusion protein, viral protein
• Biological source: Infectious salmon anemia virus
• Total number of polymer chains: 1
• Total formula weight: 8267.38

Authors

Cook, J.D.,Lee, J.E. (deposition date: 2015-02-02, release date: 2015-06-24, Last modification date: 2024-02-28)

Primary citation

Cook, J.D.,Soto-Montoya, H.,Korpela, M.K.,Lee, J.E.
Electrostatic Architecture of the Infectious Salmon Anemia Virus (ISAV) Core Fusion Protein Illustrates a Carboxyl-Carboxylate pH Sensor.
J.Biol.Chem., 290:18495-18504, 2015

PubMed Abstract: Segment 5, ORF 1 of the infectious salmon anemia virus (ISAV) genome, encodes for the ISAV F protein, which is responsible for viral-host endosomal membrane fusion during a productive ISAV infection. The entry machinery of ISAV is composed of a complex of the ISAV F and ISAV hemagglutinin esterase (HE) proteins in an unknown stoichiometry prior to receptor engagement by ISAV HE. Following binding of the receptor to ISAV HE, dissociation of the ISAV F protein from HE, and subsequent endocytosis, the ISAV F protein resolves into a fusion-competent oligomeric state. Here, we present a 2.1 Å crystal structure of the fusion core of the ISAV F protein determined at low pH. This structure has allowed us to unambiguously demonstrate that the ISAV entry machinery exhibits typical class I viral fusion protein architecture. Furthermore, we have determined stabilizing factors that accommodate the pH-dependent mode of ISAV transmission, and our structure has allowed the identification of a central coil that is conserved across numerous and varied post-fusion viral glycoprotein structures. We then discuss a mechanistic model of ISAV fusion that parallels the paramyxoviral class I fusion strategy wherein attachment and fusion are relegated to separate proteins in a similar fashion to ISAV fusion.

PubMed: 26082488
DOI: 10.1074/jbc.M115.644781

Experimental method

X-RAY DIFFRACTION (2.1 Å)