PDBsum entry 1wzg

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Oxidoreductase PDB id
Protein chains
209 a.a. *
SO4 ×6
YOM ×2
Waters ×391
* Residue conservation analysis
PDB id:
Name: Oxidoreductase
Title: Crystal structure of an artificial metalloprotein: fe(saloph type heme oxygenase
Structure: Heme oxygenase. Chain: a, b. Engineered: yes
Source: Corynebacterium diphtheriae. Organism_taxid: 1717. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
1.75Å     R-factor:   0.176     R-free:   0.215
Authors: M.Unno,N.Yokoi,T.Ueno,Y.Watanabe,M.Ikeda-Saito
Key ref:
T.Ueno et al. (2006). Design of metal cofactors activated by a protein-protein electron transfer system. Proc Natl Acad Sci U S A, 103, 9416-9421. PubMed id: 16769893 DOI: 10.1073/pnas.0510968103
04-Mar-05     Release date:   21-Feb-06    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P71119  (HMUO_CORDI) -  Heme oxygenase
215 a.a.
209 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 5 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: E.C.  - Heme oxygenase (biliverdin-producing).
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Protoheme + 3 AH2 + 3 O2 = biliverdin + Fe2+ + CO + 3 A + 3 H2O
+ 3 × AH(2)
+ 3 × O(2)
= biliverdin
+ Fe(2+)
+ CO
+ 3 × A
+ 3 × H(2)O
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     oxidation-reduction process   2 terms 
  Biochemical function     oxidoreductase activity     3 terms  


DOI no: 10.1073/pnas.0510968103 Proc Natl Acad Sci U S A 103:9416-9421 (2006)
PubMed id: 16769893  
Design of metal cofactors activated by a protein-protein electron transfer system.
T.Ueno, N.Yokoi, M.Unno, T.Matsui, Y.Tokita, M.Yamada, M.Ikeda-Saito, H.Nakajima, Y.Watanabe.
Protein-to-protein electron transfer (ET) is a critical process in biological chemistry for which fundamental understanding is expected to provide a wealth of applications in biotechnology. Investigations of protein-protein ET systems in reductive activation of artificial cofactors introduced into proteins remains particularly challenging because of the complexity of interactions between the cofactor and the system contributing to ET. In this work, we construct an artificial protein-protein ET system, using heme oxygenase (HO), which is known to catalyze the conversion of heme to biliverdin. HO uses electrons provided from NADPH/cytochrome P450 reductase (CPR) through protein-protein complex formation during the enzymatic reaction. We report that a Fe(III)(Schiff-base), in the place of the active-site heme prosthetic group of HO, can be reduced by NADPH/CPR. The crystal structure of the Fe(10-CH(2)CH(2)COOH-Schiff-base).HO composite indicates the presence of a hydrogen bond between the propionic acid carboxyl group and Arg-177 of HO. Furthermore, the ET rate from NADPH/CPR to the composite is 3.5-fold faster than that of Fe(Schiff-base).HO, although the redox potential of Fe(10-CH(2)CH(2)COOH-Schiff-base).HO (-79 mV vs. NHE) is lower than that of Fe(Schiff-base).HO (+15 mV vs. NHE), where NHE is normal hydrogen electrode. This work describes a synthetic metal complex activated by means of a protein-protein ET system, which has not previously been reported. Moreover, the result suggests the importance of the hydrogen bond for the ET reaction of HO. Our Fe(Schiff-base).HO composite model system may provide insights with regard to design of ET biosystems for sensors, catalysts, and electronics devices.
  Selected figure(s)  
Figure 1.
Fig. 1. Catalytic reaction of HO. (A) Enzymatic cycle of heme metabolism to biliverdin catalyzed by HO. The reactions shaded in blue indicate the ET step from CPR to heme to be used for the reduction of Fe^III(Schiff-base) complexes. (B) Chemical structures of heme (Left) and Fe^III(Schiff-base) (Right).
Figure 2.
Fig. 2. Close-up views of coordination geometries of the metal cofactors in the HO active-site region. Refined model coordinates for the active site region are superimposed on 2F[o] – F[c] maps contoured at 1.0 , except for heme·HO, with elements of the protein and cofactors in ball-and-stick models for top (Left) and side (Right) views. Green is carbon, and purple, red, and pink are nitrogen, oxygen, and iron, respectively. (A) Heme·HO. (B) 1·HO refined to 1.35 Å. (C) 2·HO refined to 1.85 Å. (D) 3·HO refined to 1.75 Å.
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21131047 S.Y.Lee, A.Hille, I.Kitanovic, P.Jesse, G.Henze, S.Wölfl, R.Gust, and A.Prokop (2011).
[Fe(III)(salophene)Cl], a potent iron salophene complex overcomes multiple drug resistance in lymphoma and leukemia cells.
  Leuk Res, 35, 387-393.  
20820465 A.Dalla Cort, P.De Bernardin, G.Forte, and F.Y.Mihan (2010).
Metal-salophen-based receptors for anions.
  Chem Soc Rev, 39, 3863-3874.  
20544970 L.J.Smith, A.Kahraman, and J.M.Thornton (2010).
Heme proteins--diversity in structural characteristics, function, and folding.
  Proteins, 78, 2349-2368.  
19921045 C.L.Davies, E.L.Dux, and A.K.Duhme-Klair (2009).
Supramolecular interactions between functional metal complexes and proteins.
  Dalton Trans, (), 10141-10154.  
21582175 X.Zhang (2009).
  Acta Crystallogr Sect E Struct Rep Online, 65, o512.  
21582176 X.Zhang (2009).
  Acta Crystallogr Sect E Struct Rep Online, 65, o513.  
18092096 N.Yokoi, T.Ueno, M.Unno, T.Matsui, M.Ikeda-Saito, and Y.Watanabe (2008).
Ligand design for the improvement of stability of metal complex.protein hybrids.
  Chem Commun (Camb), (), 229-231.
PDB code: 2z68
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