Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 36994.76 
• Atom Count: 2567 
• Residue Count: 334 
• Unique protein chains: 1

1DTG

HUMAN TRANSFERRIN N-LOBE MUTANT H249E

• DOI: 10.2210/pdb1DTG/pdb

• Classification: METAL TRANSPORT
• Organism(s): Homo sapiens
• Expression System: Mesocricetus auratus
• Mutation(s): 1 


• Deposited: 2000-01-12 Released: 2000-01-21 
• Deposition Author(s): MacGillivray, R.T., Bewley, M.C., Smith, C.A., He, Q.Y., Mason, A.B.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.4 Å
• R-Value Free: 0.294 
• R-Value Work: 0.198 

Literature

Mutation of the iron ligand His 249 to Glu in the N-lobe of human transferrin abolishes the dilysine "trigger" but does not significantly affect iron release.

MacGillivray, R.T., Bewley, M.C., Smith, C.A., He, Q.Y., Mason, A.B.

(2000) Biochemistry 39: 1211-1216

• PubMed: 10684598 


• PubMed Abstract: 
  

Serum transferrin is the major iron transport protein in humans. Its function depends on its ability to bind iron with very high affinity, yet to release this bound iron at the lower intracellular pH. Possible explanations for the release of iron from transferrin at low pH include protonation of a histidine ligand and the existence of a pH-sensitive "trigger" involving a hydrogen-bonded pair of lysines in the N-lobe of transferrin. We have determined the crystal structure of the His249Glu mutant of the N-lobe half-molecule of human transferrin and compared its iron-binding properties with those of the wild-type protein and other mutants. The crystal structure, determined at 2.4 A resolution (R-factor 19.8%, R(free) 29.4%), shows that Glu 249 is directly bound to iron, in place of the His ligand, and that a local movement of Lys 296 has broken the dilysine interaction. Despite the loss of this potentially pH-sensitive interaction, the H249E mutant is only slightly more acid-stable than wild-type and releases iron slightly faster. We conclude that the loss of the dilysine interaction does make the protein more acid stable but that this is counterbalanced by the replacement of a neutral ligand (His) by a negatively charged one (Glu), thus disrupting the electroneutrality of the binding site.

---

Organizational Affiliation: 

Department of Biochemistry, Massey University, Palmerston North, New Zealand.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
TRANSFERRIN	A	334	Homo sapiens	Mutation(s): 1  Gene Names: TF
Find proteins for P02787 (Homo sapiens) Go to Gene View: TF Go to UniProtKB:  P02787

Small Molecules

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

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.4 Å
• R-Value Free: 0.294 
• R-Value Work: 0.198 
• Space Group: P 4₁ 2₁ 2

Unit Cell:

Length (Å)	Angle (°)
a = 72.660	α = 90.00
b = 72.660	β = 90.00
c = 152.490	γ = 90.00

Software Package:

Software Name	Purpose
X-PLOR	phasing
ROTAVATA	data reduction
X-PLOR	model building
X-PLOR	refinement
ROTAVATA	data scaling
CCP4	data scaling
DENZO	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2000-01-12 
• Released Date: 2000-01-21 
• Deposition Author(s): MacGillivray, R.T., Bewley, M.C., Smith, C.A., He, Q.Y., Mason, A.B.

Revision History 

• Version 1.0: 2000-01-21
  Type: Initial release
• Version 1.1: 2008-04-27
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance
• Version 1.3: 2017-10-04
  Type: Refinement description