6GJE

Structure of the Amnionless(20-357)-Cubilin(36-135) complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.212 

wwPDB Validation   3D Report Full Report



Literature

Structural assembly of the megadalton-sized receptor for intestinal vitamin B12uptake and kidney protein reabsorption.

Larsen, C.Etzerodt, A.Madsen, M.Skjodt, K.Moestrup, S.K.Andersen, C.B.F.

(2018) Nat Commun 9: 5204-5204

  • DOI: 10.1038/s41467-018-07468-4
  • Primary Citation of Related Structures:  
    6GJE

  • PubMed Abstract: 
  • The endocytic receptor cubam formed by the 460-kDa protein cubilin and the 45-kDa transmembrane protein amnionless (AMN), is essential for intestinal vitamin B 12 (B 12 ) uptake and for protein (e.g. albumin) reabsorption from the ...

    The endocytic receptor cubam formed by the 460-kDa protein cubilin and the 45-kDa transmembrane protein amnionless (AMN), is essential for intestinal vitamin B 12 (B 12 ) uptake and for protein (e.g. albumin) reabsorption from the kidney filtrate. Loss of function of any of the two components ultimately leads to serious B 12 deficiency and urinary protein loss in humans (Imerslund-Gräsbeck's syndrome, IGS). Here, we present the crystal structure of AMN in complex with the amino-terminal region of cubilin, revealing a sophisticated assembly of three cubilin subunits combining into a single intertwined β-helix domain that docks to a corresponding three-faced β-helix domain in AMN. This β-helix-β-helix association thereby anchors three ligand-binding cubilin subunits to the transmembrane AMN. Electron microscopy of full-length cubam reveals a 700-800 Å long tree-like structure with the potential of dimerization into an even larger complex. Furthermore, effects of known human mutations causing IGS are explained by the structural information.


    Organizational Affiliation

    Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark. cbfa@biomed.au.dk.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein amnionless A338Homo sapiensMutation(s): 0 
Gene Names: AMNUNQ513/PRO1028
Find proteins for Q9BXJ7 (Homo sapiens)
Explore Q9BXJ7 
Go to UniProtKB:  Q9BXJ7
NIH Common Fund Data Resources
PHAROS:  Q9BXJ7
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Cubilin BCD110Homo sapiensMutation(s): 0 
Gene Names: CUBNIFCR
Find proteins for O60494 (Homo sapiens)
Explore O60494 
Go to UniProtKB:  O60494
NIH Common Fund Data Resources
PHAROS:  O60494
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.212 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.28α = 90
b = 158.84β = 90
c = 237.16γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHENIXphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Danish Council for Independent ResearchDenmark--

Revision History 

  • Version 1.0: 2018-12-19
    Type: Initial release
  • Version 1.1: 2018-12-26
    Changes: Data collection, Database references
  • Version 2.0: 2019-02-27
    Changes: Advisory, Atomic model, Data collection, Database references, Derived calculations, Structure summary
  • Version 3.0: 2019-06-12
    Changes: Advisory, Atomic model, Data collection, Database references, Derived calculations, Experimental preparation, Polymer sequence, Source and taxonomy, Structure summary