PDBsum entry 2ohj

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Oxidoreductase PDB id
Jmol PyMol
Protein chains
403 a.a. *
FMN ×4
_FE ×12
_CL ×7
Waters ×499
* Residue conservation analysis
PDB id:
Name: Oxidoreductase
Title: Crystal structure of coenzyme f420h2 oxidase (fpra), a diiro flavoprotein, inactive oxidized state
Structure: Type a flavoprotein fpra. Chain: a, b, d, e. Synonym: fmn-protein fpra, flavoprotein a. Engineered: yes
Source: Methanothermobacter thermautotrophicus organism_taxid: 145262. Strain: dszm2133. Gene: fpra, fpaa. Expressed in: escherichia coli. Expression_system_taxid: 562
2.26Å     R-factor:   0.188     R-free:   0.234
Authors: H.Seedorf,E.Warkentin,U.Ermler
Key ref: H.Seedorf et al. (2007). Structure of coenzyme F420H2 oxidase (FprA), a di-iron flavoprotein from methanogenic Archaea catalyzing the reduction of O2 to H2O. FEBS J, 274, 1588-1599. PubMed id: 17480207
10-Jan-07     Release date:   22-May-07    
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Protein chains
Pfam   ArchSchema ?
Q50497  (FPRA_METTM) -  Type A flavoprotein FprA
404 a.a.
403 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.1.-.-.-
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     oxidation-reduction process   1 term 
  Biochemical function     electron carrier activity     4 terms  


FEBS J 274:1588-1599 (2007)
PubMed id: 17480207  
Structure of coenzyme F420H2 oxidase (FprA), a di-iron flavoprotein from methanogenic Archaea catalyzing the reduction of O2 to H2O.
H.Seedorf, C.H.Hagemeier, S.Shima, R.K.Thauer, E.Warkentin, U.Ermler.
The di-iron flavoprotein F(420)H(2) oxidase found in methanogenic Archaea catalyzes the four-electron reduction of O(2) to 2H(2)O with 2 mol of reduced coenzyme F(420)(7,8-dimethyl-8-hydroxy-5-deazariboflavin). We report here on crystal structures of the homotetrameric F(420)H(2) oxidase from Methanothermobacter marburgensis at resolutions of 2.25 A, 2.25 A and 1.7 A, respectively, from which an active reduced state, an inactive oxidized state and an active oxidized state could be extracted. As found in structurally related A-type flavoproteins, the active site is formed at the dimer interface, where the di-iron center of one monomer is juxtaposed to FMN of the other. In the active reduced state [Fe(II)Fe(II)FMNH(2)], the two irons are surrounded by four histidines, one aspartate, one glutamate and one bridging aspartate. The so-called switch loop is in a closed conformation, thus preventing F(420) binding. In the inactive oxidized state [Fe(III)FMN], the iron nearest to FMN has moved to two remote binding sites, and the switch loop is changed to an open conformation. In the active oxidized state [Fe(III)Fe(III)FMN], both irons are positioned as in the reduced state but the switch loop is found in the open conformation as in the inactive oxidized state. It is proposed that the redox-dependent conformational change of the switch loop ensures alternate complete four-electron O(2) reduction and redox center re-reduction. On the basis of the known Si-Si stereospecific hydride transfer, F(420)H(2) was modeled into the solvent-accessible pocket in front of FMN. The inactive oxidized state might provide the molecular basis for enzyme inactivation by long-term O(2) exposure observed in some members of the FprA family.

Literature references that cite this PDB file's key reference

  PubMed id Reference
19337761 B.L.Victor, A.M.Baptista, and C.M.Soares (2009).
Dioxygen and nitric oxide pathways and affinity to the catalytic site of rubredoxin:oxygen oxidoreductase from Desulfovibrio gigas.
  J Biol Inorg Chem, 14, 853-862.  
19011120 T.Smutná, V.L.Gonçalves, L.M.Saraiva, J.Tachezy, M.Teixeira, and I.Hrdy (2009).
Flavodiiron protein from Trichomonas vaginalis hydrogenosomes: the terminal oxygen reductase.
  Eukaryot Cell, 8, 47-55.  
18077462 A.Di Matteo, F.M.Scandurra, F.Testa, E.Forte, P.Sarti, M.Brunori, and A.Giuffrè (2008).
The O2-scavenging flavodiiron protein in the human parasite Giardia intestinalis.
  J Biol Chem, 283, 4061-4068.
PDB code: 2q9u
18786405 M.V.Petoukhov, J.B.Vicente, P.B.Crowley, M.A.Carrondo, M.Teixeira, and D.I.Svergun (2008).
Quaternary structure of flavorubredoxin as revealed by synchrotron radiation small-angle X-ray scattering.
  Structure, 16, 1428-1436.  
17961173 A.Tholen, M.Pester, and A.Brune (2007).
Simultaneous methanogenesis and oxygen reduction by Methanobrevibacter cuticularis at low oxygen fluxes.
  FEMS Microbiol Ecol, 62, 303-312.  
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