Ebola virions contain a surface transmembrane glycoprotein (GP) that is responsible for binding to target cells and subsequent fusion of the viral and host-cell membranes. GP is expressed as a single-chain precursor that is posttranslationally processed into the disulfide-linked fragments GP1 and GP2 ...
Ebola virions contain a surface transmembrane glycoprotein (GP) that is responsible for binding to target cells and subsequent fusion of the viral and host-cell membranes. GP is expressed as a single-chain precursor that is posttranslationally processed into the disulfide-linked fragments GP1 and GP2. The GP2 subunit is thought to mediate membrane fusion. A soluble fragment of the GP2 ectodomain, lacking the fusion-peptide region and the transmembrane helix, folds into a stable, highly helical structure in aqueous solution. Limited proteolysis studies identify a stable core of the GP2 ectodomain. This 74-residue core, denoted Ebo-74, was crystallized, and its x-ray structure was determined at 1.9-A resolution. Ebo-74 forms a trimer in which a long, central three-stranded coiled coil is surrounded by shorter C-terminal helices that are packed in an antiparallel orientation into hydrophobic grooves on the surface of the coiled coil. Our results confirm the previously anticipated structural similarity between the Ebola GP2 ectodomain and the core of the transmembrane subunit from oncogenic retroviruses. The Ebo-74 structure likely represents the fusion-active conformation of the protein, and its overall architecture resembles several other viral membrane-fusion proteins, including those from HIV and influenza.
Related Citations:
Crystal Structure of the Simian Immunodeficiency Virus (Siv) Gp41 Core: Conserved Helical Interactions Underlie the Broad Inhibitory Activity of Gp41 Peptides Malashkevich, V.N., Chan, D.C., Chutkowski, C.T., Kim, P.S. (1998) Proc Natl Acad Sci U S A 95: 9134
Core Structure of Gp41 from the HIV Envelope Glycoprotein Chan, D.C., Fass, D., Berger, J.M., Kim, P.S. (1997) Cell 89: 263
Organizational Affiliation:
Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142, USA.
Download Mendeley
