5H9C

Crystal structure of the ASLV fusion protein core


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.783 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.158 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural characterization of a fusion glycoprotein from a retrovirus that undergoes a hybrid 2-step entry mechanism.

Aydin, H.Smrke, B.M.Lee, J.E.

(2013) Faseb J. 27: 5059-5071

  • DOI: 10.1096/fj.13-232371
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Entry of enveloped viruses into host cells is mediated by their surface envelope glycoproteins (Env). On the surface of the virus, Env is in a metastable, prefusion state, primed to catalyze the fusion of the viral and host membranes. An external tri ...

    Entry of enveloped viruses into host cells is mediated by their surface envelope glycoproteins (Env). On the surface of the virus, Env is in a metastable, prefusion state, primed to catalyze the fusion of the viral and host membranes. An external trigger is needed to promote the drastic conformational changes necessary for the fusion subunit to fold into the low-energy, 6-helix bundle. These triggers typically facilitate pH-independent entry at the plasma membrane or pH-dependent entry in a low-pH endosomal compartment. The α-retrovirus avian sarcoma leukosis virus (ASLV) has a rare, 2-step entry mechanism with both pH-dependent and pH-independent features. Here, we present the 2.0-Å-resolution crystal structure of the ASLV transmembrane (TM) fusion protein. Our structural and biophysical studies indicated that unlike other pH-dependent or pH-independent viral TMs, the ASLV fusion subunit is stable irrespective of pH. Two histidine residues (His490 and His492) in the chain reversal region confer stability at low pH. A structural comparison of class I viral fusion proteins suggests that the presence of a positive charge, either a histidine or arginine amino acid, stabilizes a helical dipole moment and is a signature of fusion proteins active at low pH. The structure now reveals key residues and features that explain its 2-step mechanism, and we discuss the implications of the ASLV TM structure in the context of general mechanisms required for membrane fusion.


    Organizational Affiliation

    11 King's College Cir., Rm. 6316, Toronto, ON, Canada M5S 1A8. jeff.lee@utoronto.ca.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Envelope glycoprotein gp95
A
94Avian leukosis virus RSAMutation(s): 1 
Gene Names: env
Find proteins for P03397 (Avian leukosis virus RSA)
Go to UniProtKB:  P03397
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.783 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.158 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 42.800α = 90.00
b = 42.800β = 90.00
c = 119.428γ = 120.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
Cootmodel building
PHENIXrefinement
Aimlessdata scaling
PHASERphasing
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2015-12-28 
  • Released Date: 2016-01-06 
  • Deposition Author(s): Aydin, H., Lee, J.E.

Funding OrganizationLocationGrant Number
Canadian Institutes of Health ResearchCanadaMOP-115066

Revision History 

  • Version 1.0: 2016-01-06
    Type: Initial release
  • Version 1.1: 2017-09-06
    Type: Author supporting evidence, Derived calculations