2R5L

Crystal structure of lactoperoxidase at 2.4A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal Structure of Lactoperoxidase at 2.4 A Resolution.

Singh, A.K.Singh, N.Sharma, S.Singh, S.B.Kaur, P.Bhushan, A.Srinivasan, A.Singh, T.P.

(2007) J.Mol.Biol. 376: 1060-1075

  • DOI: 10.1016/j.jmb.2007.12.012

  • PubMed Abstract: 
  • Lactoperoxidase (LPO) is a member of the mammalian peroxidase superfamily. It catalyzes the oxidation of thiocyanate and halides. Freshly isolated and purified samples of caprine LPO were saturated with ammonium iodide and crystallized using 20% poly ...

    Lactoperoxidase (LPO) is a member of the mammalian peroxidase superfamily. It catalyzes the oxidation of thiocyanate and halides. Freshly isolated and purified samples of caprine LPO were saturated with ammonium iodide and crystallized using 20% polyethylene glycol 3350 in a hanging drop vapor diffusion setup. The structure has been determined using X-ray crystallographic method and refined to R(cryst) and R(free) factors of 0.196 and 0.203, respectively. The structure determination revealed an unexpected phosphorylation of Ser198 in LPO, which is also confirmed by anti-phosphoserine antibody binding studies. The structure is also notable for observing densities for glycan chains at all the four potential glycosylation sites. Caprine LPO consists of a single polypeptide chain of 595 amino acid residues and folds into an oval-shaped structure. The structure contains 20 well-defined alpha-helices of varying lengths including a helix, H(2a), unique to LPO, and two short antiparallel beta-strands. The structure confirms that the heme group is covalently linked to the protein through two ester linkages involving carboxylic groups of Glu258 and Asp108 and modified methyl groups of pyrrole rings A and C, respectively. The heme moiety is slightly distorted from planarity, but pyrrole ring B is distorted considerably. However, an iron atom is displaced only by 0.1 A from the plane of the heme group toward the proximal site. The substrate diffusing channel in LPO is cylindrical in shape with a diameter of approximately 6 A. Two histidine residues and six buried water molecules are connected through a hydrogen-bonded chain from the distal heme cavity to the surface of protein molecule and seemingly form the basis of proton relay for catalytic action. Ten iodide ions have been observed in the structure. Out of these, only one iodide ion is located in the distal heme cavity and is hydrogen bonded to the water molecule W1. W1 is also hydrogen bonded to the heme iron as well as to distal His109. The structure contains a calcium ion that is coordinated to seven oxygen atoms and forms a typical pentagonal bipyramidal coordination geometry.


    Organizational Affiliation

    Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi - 110 029, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lactoperoxidase
A
595Capra hircusMutation(s): 0 
Gene Names: LPO
Find proteins for A3F9D6 (Capra hircus)
Go to Gene View: LPO
Go to UniProtKB:  A3F9D6
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IOD
Query on IOD

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Download CCD File 
A
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
MAN
Query on MAN

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Download CCD File 
A
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
HEM
Query on HEM

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Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
NAG
Query on NAG

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Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
A
L-PEPTIDE LINKINGC3 H8 N O6 PSER
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.196 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 54.190α = 90.00
b = 80.810β = 102.95
c = 77.040γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
SCALEPACKdata scaling
CNSrefinement
MAR345dtbdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-09-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Non-polymer description, Version format compliance