3S9L

Complex between transferrin receptor 1 and transferrin with iron in the N-Lobe, cryocooled 2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.22 Å
  • R-Value Free: 0.314 
  • R-Value Work: 0.271 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

How the binding of human transferrin primes the transferrin receptor potentiating iron release at endosomal pH.

Eckenroth, B.E.Steere, A.N.Chasteen, N.D.Everse, S.J.Mason, A.B.

(2011) Proc.Natl.Acad.Sci.USA 108: 13089-13094

  • DOI: 10.1073/pnas.1105786108
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Delivery of iron to cells requires binding of two iron-containing human transferrin (hTF) molecules to the specific homodimeric transferrin receptor (TFR) on the cell surface. Through receptor-mediated endocytosis involving lower pH, salt, and an uni ...

    Delivery of iron to cells requires binding of two iron-containing human transferrin (hTF) molecules to the specific homodimeric transferrin receptor (TFR) on the cell surface. Through receptor-mediated endocytosis involving lower pH, salt, and an unidentified chelator, iron is rapidly released from hTF within the endosome. The crystal structure of a monoferric N-lobe hTF/TFR complex (3.22-Å resolution) features two binding motifs in the N lobe and one in the C lobe of hTF. Binding of Fe(N)hTF induces global and site-specific conformational changes within the TFR ectodomain. Specifically, movements at the TFR dimer interface appear to prime the TFR to undergo pH-induced movements that alter the hTF/TFR interaction. Iron release from each lobe then occurs by distinctly different mechanisms: Binding of His349 to the TFR (strengthened by protonation at low pH) controls iron release from the C lobe, whereas displacement of one N-lobe binding motif, in concert with the action of the dilysine trigger, elicits iron release from the N lobe. One binding motif in each lobe remains attached to the same α-helix in the TFR throughout the endocytic cycle. Collectively, the structure elucidates how the TFR accelerates iron release from the C lobe, slows it from the N lobe, and stabilizes binding of apohTF for return to the cell surface. Importantly, this structure provides new targets for mutagenesis studies to further understand and define this system.


    Organizational Affiliation

    Department of Biochemistry, University of Vermont, 89 Beaumont Avenue, Burlington, VT 05405, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Transferrin receptor protein 1
A, B
654Homo sapiensMutation(s): 0 
Gene Names: TFRC
Find proteins for P02786 (Homo sapiens)
Go to Gene View: TFRC
Go to UniProtKB:  P02786
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Serotransferrin
C, D
693Homo sapiensMutation(s): 4 
Gene Names: TF
Find proteins for P02787 (Homo sapiens)
Go to Gene View: TF
Go to UniProtKB:  P02787
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

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Download CCD File 
C, D
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

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Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
CO3
Query on CO3

Download SDF File 
Download CCD File 
C, D
CARBONATE ION
C O3
BVKZGUZCCUSVTD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.22 Å
  • R-Value Free: 0.314 
  • R-Value Work: 0.271 
  • Space Group: P 43 2 2
Unit Cell:
Length (Å)Angle (°)
a = 231.676α = 90.00
b = 231.676β = 90.00
c = 168.955γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
CBASSdata collection
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-08-10
    Type: Initial release
  • Version 1.1: 2011-12-07
    Type: Derived calculations, Other
  • Version 1.2: 2011-12-14
    Type: Database references