title: A vertebrate-type ferredoxin domain in the Na+-translocating NADH dehydrogenase from Vibrio cholerae.
abstract: The Na(+)-translocating NADH:quinone oxidoreductase from Vibrio cholerae contains a single Fe-S cluster localized in subunit NqrF. Here we study the electronic properties of the Fe-S center in a truncated version of the NqrF subunit comprising only its ferredoxin-like Fe-S domain. Mössbauer spectroscopy of the Fe-S domain in the oxidized state is consistent with a binuclear Fe-S cluster with tetrahedral sulfur coordination by the cysteine residues Cys(70), Cys(76), Cys(79), and Cys(111). Important sequence motifs surrounding these cysteines are conserved in the Fe-S domain and in vertebrate-type ferredoxins. The magnetic circular dichroism spectra of the photochemically reduced Fe-S domain exhibit a striking similarity to the magnetic circular dichroism spectra of vertebrate-type ferredoxins required for the in vivo assembly of iron-sulfur clusters. This study reveals a novel function for vertebrate-type [2Fe-2S] clusters as redox cofactors in respiratory dehydrogenases.
authors.affiliation: Mikrobiologisches Institut der Eidgenössischen Technischen Hochschule, ETH-Hönggerberg, Zürich, Switzerland.
authors.forename: Po-Chi
authors.initials: PC
authors.lastname: Lin
authors.forename: Andrea
authors.initials: A
authors.lastname: Puhar
authors.forename: Karin
authors.initials: K
authors.lastname: Türk
authors.forename: Stergios
authors.initials: S
authors.lastname: Piligkos
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.forename: Julia
authors.initials: J
authors.lastname: Steuber
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D002942:Circular Dichroism; D003545:Cysteine / Q000737:chemistry; D005288:Ferredoxins / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D008280:Magnetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D017434:Protein Structure, Tertiary; D011808:Quinone Reductases / Q000737:chemistry* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012964:Sodium / Q000737:chemistry; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry*; D015204:Spectroscopy, Mossbauer / Q000379:methods; D014466:Ultraviolet Rays; D014714:Vertebrates; D014734:Vibrio cholerae / Q000201:enzymology*
chemical_list: D005288:Ferredoxins; D007506:Iron-Sulfur Proteins; D012964:Sodium; C041831:NADH dehydrogenase (quinone); D011808:Quinone Reductases; D000254:Sodium-Potassium-Exchanging ATPase; D003545:Cysteine