Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 36.52 kDa 
• Atom Count: 2714 
• Residue Count: 329 
• Unique protein chains: 1

1A8E

HUMAN SERUM TRANSFERRIN, RECOMBINANT N-TERMINAL LOBE

• DOI: 10.2210/pdb1A8E/pdb

• Classification: IRON TRANSPORT
• Organism(s): Homo sapiens
• Expression System: Cricetinae
• Mutation(s): No 


• Deposited: 1998-03-24 Released: 1998-06-17 
• Deposition Author(s): Macgillivray, R.T.A., Moore, S.A., Chen, J., Anderson, B.F., Baker, H., Luo, Y., Bewley, M., Smith, C.A., Murphy, M.E.P., Wang, Y., Mason, A.B., Woodworth, R.C., Brayer, G.D., Baker, E.N.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.60 Å
• R-Value Work: 0.181 

Literature

Two high-resolution crystal structures of the recombinant N-lobe of human transferrin reveal a structural change implicated in iron release.

MacGillivray, R.T., Moore, S.A., Chen, J., Anderson, B.F., Baker, H., Luo, Y., Bewley, M., Smith, C.A., Murphy, M.E., Wang, Y., Mason, A.B., Woodworth, R.C., Brayer, G.D., Baker, E.N.

(1998) Biochemistry 37: 7919-7928

• PubMed: 9609685 
• DOI: 10.1021/bi980355j
• Primary Citation of Related Structures:  
  1A8F, 1A8E


• PubMed Abstract: 
  

The N-lobe of human serum transferrin (hTF/2N) has been expressed in baby hamster kidney cells and crystallized in both orthorhombic (P212121) and tetragonal (P41212) space groups. Both crystal forms diffract to high resolution (1.6 and 1.8 A, respectively) and have been solved by molecular replacement. Subsequent refinement resulted in final models for the structure of hTF/2N that had crystallographic R-factors of 18.1 and 19.7% for the two crystal forms, respectively; these models represent the highest-resolution transferrin structures determined to date. The hTF/2N polypeptide has a folding pattern similar to those of other transferrins, including the presence of a deep cleft that contains the metal-binding site. In contrast to other transferrins, both crystal forms of hTF/2N display disorder at the iron-binding site; model building suggests that this disorder consists of alternative conformations of the synergistically bound carbonate anion, the side chain for Arg-124, and several solvent molecules. Subsequent refinement revealed that conformation A has an occupancy of 0.63-0. 65 and corresponds to the structure of the iron-binding site found in other transferrins. The alternative conformation B has an occupancy of 0.35-0.37; in this structure, the carbonate has rotated 30 degrees relative to the iron and the side chain for Arg-124 has moved to accommodate the new carbonate position. Several water molecules appear to stabilize the carbonate anion in the two conformations. These structures are consistent with the protonation of the carbonate and resulting partial removal of the anion from the metal; these events would occur prior to cleft opening and metal release.

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Organizational Affiliation: 

Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
SERUM TRANSFERRIN	A	329	Homo sapiens	Mutation(s): 0  Gene Names: TF, PRO1400
Find proteins for P02787 (Homo sapiens) Explore P02787  Go to UniProtKB:  P02787
NIH Common Fund Data Resources
PHAROS:  P02787 GTEx:  ENSG00000091513

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CO3	A	CARBONATE ION C O3 BVKZGUZCCUSVTD-UHFFFAOYSA-L
FE	A	FE (III) ION Fe VTLYFUHAOXGGBS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.60 Å
• R-Value Work: 0.181 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 45.12	α = 90
b = 57.91	β = 90
c = 135.64	γ = 90

Software Package:

Software Name	Purpose
R-AXIS	data collection
R-AXIS	data reduction
TNT	refinement
R-AXIS	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1998-03-24 
• Released Date: 1998-06-17 
Deposition Author(s): Macgillivray, R.T.A., Moore, S.A., Chen, J., Anderson, B.F., Baker, H., Luo, Y., Bewley, M., Smith, C.A., Murphy, M.E.P., Wang, Y., Mason, A.B., Woodworth, R.C., Brayer, G.D., Baker, E.N.

Revision History 

• Version 1.0: 1998-06-17
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance