Crystal structure of the TG and EGF-like domains of ALK

Experimental Data Snapshot

  • Resolution: 3.00 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.221 

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Structural basis of cytokine-mediated activation of ALK family receptors.

De Munck, S.Provost, M.Kurikawa, M.Omori, I.Mukohyama, J.Felix, J.Bloch, Y.Abdel-Wahab, O.Bazan, J.F.Yoshimi, A.Savvides, S.N.

(2021) Nature 600: 143-147

  • DOI: https://doi.org/10.1038/s41586-021-03959-5
  • Primary Citation of Related Structures:  
    7NWZ, 7NX0, 7NX1, 7NX2, 7NX3, 7NX4

  • PubMed Abstract: 

    Anaplastic lymphoma kinase (ALK) 1 and the related leukocyte tyrosine kinase (LTK) 2 are recently deorphanized receptor tyrosine kinases 3 . Together with their activating cytokines, ALKAL1 and ALKAL2 4-6 (also called FAM150A and FAM150B or AUGβ and AUGα, respectively), they are involved in neural development 7 , cancer 7-9 and autoimmune diseases 10 . Furthermore, mammalian ALK recently emerged as a key regulator of energy expenditure and weight gain 11 , consistent with a metabolic role for Drosophila ALK 12 . Despite such functional pleiotropy and growing therapeutic relevance 13,14 , structural insights into ALK and LTK and their complexes with cognate cytokines have remained scarce. Here we show that the cytokine-binding segments of human ALK and LTK comprise a novel architectural chimera of a permuted TNF-like module that braces a glycine-rich subdomain featuring a hexagonal lattice of long polyglycine type II helices. The cognate cytokines ALKAL1 and ALKAL2 are monomeric three-helix bundles, yet their binding to ALK and LTK elicits similar dimeric assemblies with two-fold symmetry, that tent a single cytokine molecule proximal to the cell membrane. We show that the membrane-proximal EGF-like domain dictates the apparent cytokine preference of ALK. Assisted by these diverse structure-function findings, we propose a structural and mechanistic blueprint for complexes of ALK family receptors, and thereby extend the repertoire of ligand-mediated dimerization mechanisms adopted by receptor tyrosine kinases.

  • Organizational Affiliation

    Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ALK tyrosine kinase receptor389Homo sapiensMutation(s): 0 
Gene Names: ALK
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UM73 (Homo sapiens)
Explore Q9UM73 
Go to UniProtKB:  Q9UM73
GTEx:  ENSG00000171094 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9UM73
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.00 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.221 
  • Space Group: I 41
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.93α = 90
b = 84.93β = 90
c = 148.666γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Research Foundation - Flanders (FWO)Belgium--

Revision History  (Full details and data files)

  • Version 1.0: 2021-10-27
    Type: Initial release
  • Version 1.1: 2021-12-15
    Changes: Database references
  • Version 1.2: 2024-01-31
    Changes: Data collection, Refinement description