1HTM

STRUCTURE OF INFLUENZA HAEMAGGLUTININ AT THE PH OF MEMBRANE FUSION

• PDB DOI: https://doi.org/10.2210/pdb1HTM/pdb

• Classification: VIRAL PROTEIN
• Organism(s): uncultured beta proteobacterium UMTRA-608
• Mutation(s): No 


• Deposited: 1994-11-02 Released: 1995-02-14 
• Deposition Author(s): Bullough, P.A., Hughson, F.M., Skehel, J.J., Wiley, D.C.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.291 
• R-Value Work: 0.222 
• R-Value Observed: 0.222 

Literature

Structure of influenza haemagglutinin at the pH of membrane fusion.

Bullough, P.A., Hughson, F.M., Skehel, J.J., Wiley, D.C.

(1994) Nature 371: 37-43

• PubMed: 8072525 
• DOI: https://doi.org/10.1038/371037a0
• Primary Citation of Related Structures:  
  1HTM


• PubMed Abstract: 
  

  Low pH induces a conformational change in the influenza virus haemagglutinin, which then mediates fusion of the viral and host cell membranes. The three-dimensional structure of a fragment of the haemagglutinin in this conformation reveals a major refolding of the secondary and tertiary structure of the molecule. The apolar fusion peptide moves at least 100 A to one tip of the molecule. At the other end a helical segment unfolds, a subdomain relocates reversing the chain direction, and part of the structure becomes disordered.

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Organizational Affiliation: 

Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 6-mer - A3B2C1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 6-mer - A3B1C1D1 

Local Symmetry: Cyclic - C3  (Explore in 3D)
Local Stoichiometry: Homo 3-mer - A3 Local Symmetry: Cyclic - C2  (Explore in 3D)
Local Stoichiometry: Homo 2-mer - B2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 57.13 kDa 
• Atom Count: 3,129 
• Modelled Residue Count: 379 
• Deposited Residue Count: 495 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
HEMAGGLUTININ HA1 CHAIN	A, C, E	27	uncultured beta proteobacterium UMTRA-608	Mutation(s): 0
UniProt
Find proteins for P03437 (Influenza A virus (strain A/Aichi/2/1968 H3N2)) Explore P03437  Go to UniProtKB:  P03437

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
HEMAGGLUTININ HA2 CHAIN	B, D, F	138	uncultured beta proteobacterium UMTRA-608	Mutation(s): 0
UniProt
Find proteins for P03437 (Influenza A virus (strain A/Aichi/2/1968 H3N2)) Explore P03437  Go to UniProtKB:  P03437

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.291 
• R-Value Work: 0.222 
• R-Value Observed: 0.222 
• Space Group: C 2 2 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 168.7	α = 90
b = 231.7	β = 90
c = 53.8	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1995-02-14 
Deposition Author(s): Bullough, P.A., Hughson, F.M., Skehel, J.J., Wiley, D.C.

Revision History  

• Version 1.0: 1995-02-14
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-06-05
  Changes: Data collection, Database references, Other
• Version 1.4: 2024-10-30
  Changes: Structure summary