8FAX | pdb_00008fax

Fab 1249A8-MERS Stem Helix Complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 
    0.240 (Depositor), 0.242 (DCC) 
  • R-Value Work: 
    0.182 (Depositor), 0.184 (DCC) 
  • R-Value Observed: 
    0.185 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

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This is version 1.2 of the entry. See complete history

Literature

Structure and epitope of a neutralizing monoclonal antibody that targets the stem helix of beta coronaviruses.

Deshpande, A.Schormann, N.Piepenbrink, M.S.Martinez Sobrido, L.Kobie, J.J.Walter, M.R.

(2023) FEBS J 290: 3422-3435

  • DOI: https://doi.org/10.1111/febs.16777
  • Primary Citation Related Structures: 
    8FAX

  • PubMed Abstract: 

    Monoclonal antibodies that retain neutralizing activity against multiple coronavirus (CoV) lineages and variants of concern (VoC) must be developed to protect against future pandemics. These broadly neutralizing MAbs (BNMAbs) may be used as therapeutics and/or to assist in the rational design of vaccines that induce BNMAbs. 1249A8 is a BNMAb that targets the stem helix (SH) region of CoV spike (S) protein and neutralizes Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) original strain, delta, and omicron VoC, Severe Acute Respiratory Syndrome CoV (SARS-CoV), and Middle East Respiratory Syndrome CoV (MERS-CoV). To understand its mechanism of action, the crystal structure of 1249A8 bound to a MERS-CoV SH peptide was determined at 2.1 Å resolution. BNMAb 1249A8 mimics the SARS-CoV-2 S loop residues 743-749, which interacts with the N-terminal end of the SH helix in the S post-fusion conformation. The conformation of 1249A8-bound SH is distinct from the SH conformation observed in the post-fusion SARS-CoV-2 S structure, suggesting 1249A8 disrupts the secondary structure and refolding events required for CoV post-fusion S to initiate membrane fusion and ultimately infection. This study provides novel insights into the neutralization mechanisms of SH-targeting CoV BNMAbs that may inform vaccine development and the design of optimal BNMAb therapeutics.


  • Organizational Affiliation
    • Department of Microbiology, University of Alabama at Birmingham, AL, USA.

Macromolecule Content 

  • Total Structure Weight: 50.21 kDa 
  • Atom Count: 3,667 
  • Modeled Residue Count: 446 
  • Deposited Residue Count: 461 
  • Unique protein chains: 3

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
1249A8-HC221Homo sapiensMutation(s): 0 
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
1249A8-LC217Homo sapiensMutation(s): 0 
Find similar proteins by:  Sequence   |   3D Structure  
Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
Spike glycoproteinC [auth L]23Middle East respiratory syndrome-related coronavirusMutation(s): 0 
UniProt
Find proteins for K9N5Q8 (Middle East respiratory syndrome-related coronavirus (isolate United Kingdom/H123990006/2012))
Explore K9N5Q8 
Go to UniProtKB:  K9N5Q8
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupK9N5Q8
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CL

Query on CL



Download:Ideal Coordinates CCD File
L [auth B]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
MG

Query on MG



Download:Ideal Coordinates CCD File
D [auth A]
E [auth A]
F [auth A]
G [auth A]
H [auth A]
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
M [auth L]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free:  0.240 (Depositor), 0.242 (DCC) 
  • R-Value Work:  0.182 (Depositor), 0.184 (DCC) 
  • R-Value Observed: 0.185 (Depositor) 
Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.714α = 90
b = 56.308β = 91.191
c = 76.124γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
DIALSdata reduction
DIALSdata scaling
PHASERphasing
ARP/wARPmodel building

Structure Validation

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Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United StatesAI161175

Revision History  (Full details and data files)

  • Version 1.0: 2023-05-03
    Type: Initial release
  • Version 1.1: 2023-07-19
    Changes: Database references
  • Version 1.2: 2024-11-20
    Changes: Data collection, Structure summary