PDBsum entry 3fd4

Viral protein

PDB id: 3fd4

Contents

Protein chains

140 a.a. *

147 a.a. *

Waters ×281

* Residue conservation analysis

PDB id:

3fd4

Name:

Viral protein

Title:

Crystal structure of epstein-barr virus gp42 protein

Structure:

Glycoprotein gp42. Chain: a, b. Engineered: yes

Source:

Human herpesvirus 4 (strain b95-8). Organism_taxid: 10377. Strain: b95-8. Gene: bzlf2. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108.

Resolution:

2.40Å R-factor: 0.217 R-free: 0.242

Authors:

A.Kirschner,T.Jardetzky

Key ref:

A.N.Kirschner et al. (2009). Structure of Epstein-Barr virus glycoprotein 42 suggests a mechanism for triggering receptor-activated virus entry. Structure, 17, 223-233. PubMed id: 19217393 DOI: 10.1016/j.str.2008.12.010

Date:

24-Nov-08 Release date: 23-Jun-09

Protein chain

P03205  (GP42_EBVB9) -  Glycoprotein 42 from Epstein-Barr virus (strain B95-8)

Seq: 223 a.a.

Struc: 140 a.a.

Protein chain

P03205  (GP42_EBVB9) -  Glycoprotein 42 from Epstein-Barr virus (strain B95-8)

Seq: 223 a.a.

Struc: 147 a.a.

DOI no: 10.1016/j.str.2008.12.010

Structure 17:223-233 (2009)

PubMed id: 19217393

Structure of Epstein-Barr virus glycoprotein 42 suggests a mechanism for triggering receptor-activated virus entry.

A.N.Kirschner, J.Sorem, R.Longnecker, T.S.Jardetzky.

ABSTRACT

Epstein-Barr virus requires glycoproteins gH/gL, gB, and gp42 to fuse its lipid envelope with B cells. Gp42 is a type II membrane protein consisting of a flexible N-terminal region, which binds gH/gL, and a C-terminal lectin-like domain that binds to the B-cell entry receptor human leukocyte antigen (HLA) class II. Gp42 triggers membrane fusion after HLA binding, a process that requires simultaneous binding to gH/gL and a functional hydrophobic pocket in the lectin domain adjacent to the HLA binding site. Here we present the structure of gp42 in its unbound form. Comparisons to the previously determined structure of a gp42:HLA complex reveals additional N-terminal residues forming part of the gH/gL binding site and structural changes in the receptor binding domain. Although the core of the lectin domain remains similar, significant shifts in two loops and an alpha helix bordering the essential hydrophobic pocket suggest a structural mechanism for triggering fusion.

Selected figure(s)

Figure 1.
Figure 1. Two Gp42 Molecules in the Asymmetric Unit
Ribbon diagrams of the two gp42 molecules in the asymmetric unit in side (A) and top (B) views, colored from blue to red starting at the N terminus. The N and C termini of each chain are marked. Molecule B has a longer N terminus (starting at residue 76) than molecule A (starting at residue 82). Both N termini form extended regions heading away from the C-terminal C-type lectin domain (CTLD). The broad hydrophobic pockets are indicated in (B).

Figure 3.
Figure 3. Residues 87–93 Pack Identically into Symmetry-Related HLA Binding Sites
The gp42 N-terminal residues that are immediately proximal to the CTLD extend similarly in the two copies of the gp42 molecules in the asymmetric unit and make identical packing interactions with the HLA binding site of a neighboring molecule.
(A) The overlay of the two gp42 molecules of the asymmetric unit is shown in beige, with the N-terminal residues in yellow stick representation that form this packing interaction with the neighboring gp42 (blue). The HLA binding site is indicated and the corresponding residues are shown as sticks.
(B) A zoomed-in view of this packing interaction is shown, along with the packing of residue F88 against hydrophobic HLA binding residues.

The above figures are reprinted by permission from Cell Press: Structure (2009, 17, 223-233) copyright 2009.

Figures were selected by an automated process.