title: Structural and Functional Studies on the Marburg Virus GP2 Fusion Loop.
abstract: Marburg virus (MARV) and the ebolaviruses belong to the family Filoviridae (the members of which are filoviruses) that cause severe hemorrhagic fever. Infection requires fusion of the host and viral membranes, a process that occurs in the host cell endosomal compartment and is facilitated by the envelope glycoprotein fusion subunit, GP2. The N-terminal fusion loop (FL) of GP2 is a hydrophobic disulfide-bonded loop that is postulated to insert and disrupt the host endosomal membrane during fusion. Here, we describe the first structural and functional studies of a protein corresponding to the MARV GP2 FL. We found that this protein undergoes a pH-dependent conformational change, as monitored by circular dichroism and nuclear magnetic resonance. Furthermore, we report that, under low pH conditions, the MARV GP2 FL can induce content leakage from liposomes. The general aspects of this pH-dependent structure and lipid-perturbing behavior are consistent with previous reports on Ebola virus GP2 FL. However, nuclear magnetic resonance studies in lipid bicelles and mutational analysis indicate differences in structure exist between MARV and Ebola virus GP2 FL. These results provide new insight into the mechanism of MARV GP2-mediated cell entry.
authors: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York.
authors: Nina
authors: N
authors: Liu
authors: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York.
authors: Yisong
authors: Y
authors: Tao
authors: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York.
authors: Michael D
authors: MD
authors: Brenowitz
authors: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York.
authors: Mark E
authors: ME
authors: Girvin
authors: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York.
authors: Jonathan R
authors: JR
authors: Lai
mesh_terms: D000818:Animals; D004926:Escherichia coli / Q000821:virology; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000378:metabolism; D008379:Marburg Virus Disease / Q000821:virology; D029024:Marburgvirus / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000378:metabolism*; D053586:Virus Internalization
chemical_list: D008055:Lipids; D008081:Liposomes; D014759:Viral Envelope Proteins; C113189:envelope glycoprotein, Ebola virus
keywords: Marburg virus; envelope glycoprotein; viral entry; viral membrane fusion