5HBC

Intermediate structure of iron-saturated C-lobe of bovine lactoferrin at 2.79 Angstrom resolution indicates the softening of iron coordination


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.79 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.209 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structure of iron saturated C-lobe of bovine lactoferrin at pH 6.8 indicates a weakening of iron coordination

Rastogi, N.Singh, A.Singh, P.K.Tyagi, T.K.Pandey, S.Shin, K.Kaur, P.Sharma, S.Singh, T.P.

(2016) Proteins 84: 591-599

  • DOI: 10.1002/prot.25004
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The bilobal lactoferrin is an approximately 76 kDa glycoprotein. It sequesters two Fe(3+) ions together with two CO(3)(2-) ions. The C-terminal half (residues, Tyr342-Arg689, C-lobe) of bovine lactoferrin (BLF) (residues Ala1-Arg689) was prepared by ...

    The bilobal lactoferrin is an approximately 76 kDa glycoprotein. It sequesters two Fe(3+) ions together with two CO(3)(2-) ions. The C-terminal half (residues, Tyr342-Arg689, C-lobe) of bovine lactoferrin (BLF) (residues Ala1-Arg689) was prepared by limited proteolysis using trypsin. Both C-lobe and intact BLF were saturated to 100%. Both of them retained up to nearly 85% of iron at pH 6.5. At pH 5.0, C-lobe retained 75% of iron whereas intact protein could retain only slightly more than 60%. At pH 4.0 both contained 25% iron and at pH 2.0 they were left with iron concentration of only 10%. The structure of iron saturated C-lobe was determined at 2.79 Å resolution and refined to R(cryst) and R(free) factors of 0.205 and 0.273, respectively. The structure contains two crystallographically independent molecules, A and B. They were found to have identical structures with an r.m.s. shift of 0.5 Å for their C(α) atoms. A high solvent content of 66% was observed in the crystals. The average value of an overall B-factor was 68.0 Å(2). The distance of 2.9 Å observed for the coordination bond between Fe(3+) ion and N(e2) of His595 appeared to be considerably longer than the normally observed values of 1.9-2.2 Å. This indicated that the coordination bond involving His595 may be absent. Other coordination distances were observed in the range of 2.1-2.3 Å. Based on the present structure of iron saturated C-lobe, it may be stated that His595 is the first residue to dissociate from ferric ion when the pH is lowered.


    Organizational Affiliation

    Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lactotransferrin
A, B
348Bos taurusMutation(s): 0 
Gene Names: LTF
EC: 3.4.21
Find proteins for P24627 (Bos taurus)
Go to UniProtKB:  P24627
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

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

Download CCD File 
A, B
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
BCT
Query on BCT

Download CCD File 
A, B
BICARBONATE ION
C H O3
BVKZGUZCCUSVTD-UHFFFAOYSA-M
 Ligand Interaction
FE
Query on FE

Download CCD File 
A, B
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.79 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.209 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 159.654α = 90
b = 82.58β = 128.08
c = 107.694γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-01-20
    Type: Initial release
  • Version 1.1: 2016-07-20
    Changes: Database references