scholarly journals Proteomics Computational Analyses Suggest that the Envelope Glycoproteins of Segmented Jingmen Flavi-Like Viruses Are Class II Viral Fusion Proteins (β-Penetrenes) with Mucin-Like Domains

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 260 ◽  
Author(s):  
Courtney Garry ◽  
Robert Garry
Keyword(s):  
Fusion Proteins ◽  
Domain Architecture ◽  
Class Ii ◽  
Structural Features ◽  
Beta Sheets ◽  
Viral Fusion ◽  
Alpha Helices ◽  
Worldwide Distribution ◽  
Viral Fusion Proteins ◽  
Computational Analyses

Jingmen viruses are newly described segmented flavi-like viruses that have a worldwide distribution in ticks and have been associated with febrile illnesses in humans. Computational analyses were used to predict that Jingmen flavi-like virus glycoproteins have structural features of class II viral fusion proteins, including an ectodomain consisting of beta-sheets and short alpha-helices, a fusion peptide with interfacial hydrophobicity and a three-domain architecture. Jingmen flavi-like virus glycoproteins have a sequence enriched in serine, threonine, and proline at the amino terminus, which is a feature of mucin-like domains. Several of the serines and threonines are predicted be modified by the addition of O-linked glycans. Some of the glycoproteins are predicted to have an additional mucin-like domain located prior to the transmembrane anchor, whereas others are predicted to have a stem consisting of two alpha-helices. The flavivirus envelope protein and Jingmen flavi-virus glycoproteins may have diverged from a common class II precursor glycoprotein with a mucin-like domain or domains acquired after divergence.

scholarly journals Proteomics Computational Analyses Suggest That the Envelope Glycoproteins of Segmented Flavi-Like Jingmen Group Viruses Are Class II Viral Fusion Proteins (β-Penetrenes) with Mucin-Like Domains

2020 ◽  
Author(s):  
Courtney E. Garry ◽  
Robert F. Garry
Keyword(s):  
Fusion Proteins ◽  
Domain Architecture ◽  
Class Ii ◽  
Structural Features ◽  
Beta Sheets ◽  
Viral Fusion ◽  
Alpha Helices ◽  
Worldwide Distribution ◽  
Viral Fusion Proteins ◽  
Computational Analyses

Jingmen viruses are newly described segmented flavi-like viruses that have a worldwide distribution in ticks and have been associated with febrile illnesses in humans. Computational analyses were used to predict that Jingmen flavi-like virus glycoproteins have structural features of class II viral fusion proteins, including an ectodomain consisting of beta-sheets and short alpha-helices, a fusion peptide with interfacial hydrophobicity and a three domain architecture. Jingmen flavi-like virus glycoproteins have a sequence enriched in serine, threonine and proline at the amino terminus, which is a feature of mucin-like domains. Several of the serines and threonines are predicted be modified by the addition of O-linked glycans. Some of the glycoproteins are predicted to have an additional mucin-like domain located prior to the transmembrane anchor, whereas others are predicted to have a stem consisting of two alpha-helices. The flavivirus envelope protein and Jingmen flavi-virus glycoproteins may have diverged from a common class II precursor glycoprotein with a mucin-like domain or domains acquired after divergence.

scholarly journals Characterization of EBV gB indicates properties of both class I and class II viral fusion proteins

Virology ◽  
2007 ◽  
Vol 368 (1) ◽  
pp. 102-113 ◽  
Author(s):  
Marija Backovic ◽  
George P. Leser ◽  
Robert A. Lamb ◽  
Richard Longnecker ◽  
Theodore S. Jardetzky
Keyword(s):  
Fusion Proteins ◽  
Class Ii ◽  
Class I ◽  
Viral Fusion ◽  
Viral Fusion Proteins

scholarly journals Purification and Crystallization Reveal Two Types of Interactions of the Fusion Protein Homotrimer of Semliki Forest Virus

2004 ◽  
Vol 78 (7) ◽  
pp. 3514-3523 ◽  
Author(s):  
Don L. Gibbons ◽  
Brigid Reilly ◽  
Anna Ahn ◽  
Marie-Christine Vaney ◽  
Armelle Vigouroux ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Fusion Proteins ◽  
Semliki Forest Virus ◽  
Three Dimensional ◽  
Class Ii ◽  
Class I ◽  
Structural Basis ◽  
Viral Fusion ◽  
Purification Method ◽  
Viral Fusion Proteins

ABSTRACT The fusion proteins of the alphaviruses and flaviviruses have a similar native structure and convert to a highly stable homotrimer conformation during the fusion of the viral and target membranes. The properties of the alpha- and flavivirus fusion proteins distinguish them from the class I viral fusion proteins, such as influenza virus hemagglutinin, and establish them as the first members of the class II fusion proteins. Understanding how this new class carries out membrane fusion will require analysis of the structural basis for both the interaction of the protein subunits within the homotrimer and their interaction with the viral and target membranes. To this end we report a purification method for the E1 ectodomain homotrimer from the alphavirus Semliki Forest virus. The purified protein is trimeric, detergent soluble, retains the characteristic stability of the starting homotrimer, and is free of lipid and other contaminants. In contrast to the postfusion structures that have been determined for the class I proteins, the E1 homotrimer contains the fusion peptide region responsible for interaction with target membranes. This E1 trimer preparation is an excellent candidate for structural studies of the class II viral fusion proteins, and we report conditions that generate three-dimensional crystals suitable for analysis by X-ray diffraction. Determination of the structure will provide our first high-resolution views of both the low-pH-induced trimeric conformation and the target membrane-interacting region of the alphavirus fusion protein.

scholarly journals Domain III from class II fusion proteins functions as a dominant-negative inhibitor of virus membrane fusion

2005 ◽  
Vol 171 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Maofu Liao ◽  
Margaret Kielian
Keyword(s):  
Membrane Fusion ◽  
Fusion Proteins ◽  
Class Ii ◽  
Dominant Negative ◽  
Viral Fusion ◽  
Fusion Peptides ◽  
Fusion Reactions ◽  
Dominant Negative Inhibitor ◽  
Viral Fusion Proteins ◽  
Domain Iii

Alphaviruses and flaviviruses infect cells through low pH-dependent membrane fusion reactions mediated by their structurally similar viral fusion proteins. During fusion, these class II viral fusion proteins trimerize and refold to form hairpin-like structures, with the domain III and stem regions folded back toward the target membrane-inserted fusion peptides. We demonstrate that exogenous domain III can function as a dominant-negative inhibitor of alphavirus and flavivirus membrane fusion and infection. Domain III binds stably to the fusion protein, thus preventing the foldback reaction and blocking the lipid mixing step of fusion. Our data reveal the existence of a relatively long-lived core trimer intermediate with which domain III interacts to initiate membrane fusion. These novel inhibitors of the class II fusion proteins show cross-inhibition within the virus genus and suggest that the domain III–core trimer interaction can serve as a new target for the development of antiviral reagents.

Structural comparison of three viral “fusion” proteins

1991 ◽  
Vol 19 (3) ◽  
pp. 312S-312S
Author(s):  
BRUCE H NICHOLSON ◽  
MAHMOUD NAASE
Keyword(s):  
Fusion Proteins ◽  
Viral Fusion ◽  
Structural Comparison ◽  
Viral Fusion Proteins

scholarly journals New Biophysical Approaches Reveal the Dynamics and Mechanics of Type I Viral Fusion Machinery and Their Interplay with Membranes

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 413 ◽  
Author(s):  
Mark A. Benhaim ◽  
Kelly K. Lee
Keyword(s):  
Membrane Fusion ◽  
Conformational Changes ◽  
Viral Entry ◽  
Fusion Proteins ◽  
Structural Changes ◽  
Fusion Reaction ◽  
Type I ◽  
Viral Fusion ◽  
Technological Advances ◽  
Viral Fusion Proteins

Protein-mediated membrane fusion is a highly regulated biological process essential for cellular and organismal functions and infection by enveloped viruses. During viral entry the membrane fusion reaction is catalyzed by specialized protein machinery on the viral surface. These viral fusion proteins undergo a series of dramatic structural changes during membrane fusion where they engage, remodel, and ultimately fuse with the host membrane. The structural and dynamic nature of these conformational changes and their impact on the membranes have long-eluded characterization. Recent advances in structural and biophysical methodologies have enabled researchers to directly observe viral fusion proteins as they carry out their functions during membrane fusion. Here we review the structure and function of type I viral fusion proteins and mechanisms of protein-mediated membrane fusion. We highlight how recent technological advances and new biophysical approaches are providing unprecedented new insight into the membrane fusion reaction.

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