PDBsum entry 1ebo

Viral protein

PDB id: 1ebo

Contents

Protein chains

(+ 0 more) 112 a.a. *

Metals

_ZN ×3

_CL ×2

* Residue conservation analysis

References listed in PDB file

Key reference

Title

Crystal structure of the ebola virus membrane fusion subunit, Gp2, From the envelope glycoprotein ectodomain.

Authors

W.Weissenhorn, A.Carfí, K.H.Lee, J.J.Skehel, D.C.Wiley.

Ref.

Mol Cell, 1998, 2, 605-616. [DOI no: 10.1016/S1097-2765(00)80159-8]

PubMed id

9844633

Abstract

We have determined the structure of GP2 from the Ebola virus membrane fusion glycoprotein by X-ray crystallography. The molecule contains a central triple-stranded coiled coil followed by a disulfide-bonded loop homologous to an immunosuppressive sequence in retroviral glycoproteins, which reverses the chain direction and connects to an alpha helix packed antiparallel to the core helices. The structure suggests that fusion peptides near the N termini form disulfide-bonded loops at one end of the molecule and that the C-terminal membrane anchors are at the same end. In this conformation, GP2 could both bridge two membranes and facilitate their apposition to initiate membrane fusion. We also find a heptad irregularity like that in low-pH-induced influenza HA2 and a solvent ion trapped in a coiled coil like that in retroviral TMs.

Figure 4.
Figure 4. Comparison of GP2 with the Structures of Viral and Cellular Membrane Fusion Proteins(A) Recombinant Ebola Zaire GP2.(B) Recombinant Mo-55 from the TM subunit of MoMuLv ([24]).(C) Low-pH-treated HA2 from influenza virus ([8]).(D) Recombinant, proteolysis-resistant core of HIV-1 gp41 ([70]).(E) Recombinant SIV gp41, NMR structure ([9]).(F) Recombinant core coiled segments of the SNARES syntaxin 1-A (blue), synaptobrevin-II (light blue), and SNAP-25B (yellow) ([63]). This figure was created with RIBBONS ( [11]).

Figure 6.
Figure 6. Hypothetical Model of Some Steps in the Membrane Fusion Mechanism(A) and (B) represent hypothetical intermediates and are based on Figure 3 of [70] (see text). Fusion peptides labeled F are colored red. GP2 transmembrane anchors are labeled A. The GP2 outer layer α helices are colored light blue; the N-terminal, core coiled coil is dark blue; disulfide bonds are yellow. Ngp2 and Ngp1 label the proposed location of the N termini of those polypeptide chains. The gray spheres represent the receptor-binding domain of GP1. The picture also incorporates suggestions that more than one trimer might be involved in forming an initial fusion pore ( [22]) and that the bilayers may be distorted with molecules entering at an angle ( [51 and 65]), which in some way results in distortions to the membrane that favor membrane fusion (e.g. [17]).

The above figures are reprinted by permission from Cell Press: Mol Cell (1998, 2, 605-616) copyright 1998.