1R14

Carbohydrate recognition and neck domains of surfactant protein A (Sp-A) containing samarium


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.222 

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This is version 1.4 of the entry. See complete history


Literature

Crystal structure of trimeric carbohydrate recognition and neck domains of surfactant protein A

Head, J.F.Mealy, T.R.McCormack, F.X.Seaton, B.A.

(2003) J Biol Chem 278: 43254-43260

  • DOI: https://doi.org/10.1074/jbc.M305628200
  • Primary Citation of Related Structures:  
    1R13, 1R14

  • PubMed Abstract: 

    Surfactant protein A (SP-A), one of four proteins associated with pulmonary surfactant, binds with high affinity to alveolar phospholipid membranes, positioning the protein at the first line of defense against inhaled pathogens. SP-A exhibits both calcium-dependent carbohydrate binding, a characteristic of the collectin family, and specific interactions with lipid membrane components. The crystal structure of the trimeric carbohydrate recognition domain and neck domain of SP-A was solved to 2.1-A resolution with multiwavelength anomalous dispersion phasing from samarium. Two metal binding sites were identified, one in the highly conserved lectin site and the other 8.5 A away. The interdomain carbohydrate recognition domain-neck angle is significantly less in SP-A than in the homologous collectins, surfactant protein D, and mannose-binding protein. This conformational difference may endow the SP-A trimer with a more extensive hydrophobic surface capable of binding lipophilic membrane components. The appearance of this surface suggests a putative binding region for membrane-derived SP-A ligands such as phosphatidylcholine and lipid A, the endotoxic lipid component of bacterial lipopolysaccharide that mediates the potentially lethal effects of Gram-negative bacterial infection.


  • Organizational Affiliation

    Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts 02118, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Pulmonary surfactant-associated protein A148Rattus norvegicusMutation(s): 1 
Gene Names: SFTPA1 OR SFTPA OR SFTP1 OR SFTP-1
UniProt
Find proteins for P08427 (Rattus norvegicus)
Explore P08427 
Go to UniProtKB:  P08427
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08427
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.222 
  • Space Group: P 63
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 97.68α = 90
b = 97.68β = 90
c = 44.4γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing
CNSrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-11-11
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.4: 2024-10-09
    Changes: Data collection, Structure summary