The three dimensional structure of NK cell receptor Nkp44, a triggering partner in natural cytotoxicity

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.240 

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The Three-Dimensional Structure of the Human Nk Cell Receptor Nkp44, a Triggering Partner in Natural Cytotoxicity

Cantoni, C.Ponassi, M.Biassoni, R.Conte, R.Spallarossa, A.Moretta, A.Moretta, L.Bolognesi, M.Bordo, D.

(2003) Structure 11: 725

  • DOI: https://doi.org/10.1016/s0969-2126(03)00095-9
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Natural killer (NK) cells direct cytotoxicity against tumor or virally infected cells. NK cell activation depends on a fine balance between inhibitory and activating receptors. NKp44 is a cytotoxicity activating receptor composed of one Ig-like extracellular domain, a transmembrane segment, and a cytoplasmic domain. The 2.2 A crystal structure shows that the NKp44 Ig domain forms a saddle-shaped dimer, where a charged surface groove protrudes from the core structure in each subunit. NKp44 Ig domain disulfide bridge topology defines a new Ig structural subfamily. The data presented are a first step toward understanding the molecular basis for ligand recognition by natural cytotoxicity receptors, whose key role in the immune system is established, but whose cellular ligands are still elusive.

  • Organizational Affiliation

    Dipartimento di Medicina Sperimentale, Università di Genova, Via L.B. Alberti 1, 16132 Genova, Italy.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
NK CELL ACTIVATING RECEPTOR122Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for O95944 (Homo sapiens)
Explore O95944 
Go to UniProtKB:  O95944
GTEx:  ENSG00000096264 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO95944
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.240 
  • Space Group: P 62 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.437α = 90
b = 60.437β = 90
c = 197.253γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-06-11
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance