title: Molecular basis of proton motive force generation: structure of formate dehydrogenase-N.
abstract: The structure of the membrane protein formate dehydrogenase-N (Fdn-N), a major component of Escherichia coli nitrate respiration, has been determined at 1.6 angstroms. The structure demonstrates 11 redox centers, including molybdopterin-guanine dinucleotides, five [4Fe-4S] clusters, two heme b groups, and a menaquinone analog. These redox centers are aligned in a single chain, which extends almost 90 angstroms through the enzyme. The menaquinone reduction site associated with a possible proton pathway was also characterized. This structure provides critical insights into the proton motive force generation by redox loop, a common mechanism among a wide range of respiratory enzymes.
authors.affiliation: Division of Biomedical Sciences, Imperial College, London SW7 2AZ, UK.
authors.forename: Mika
authors.initials: M
authors.lastname: Jormakka
authors.forename: Susanna
authors.initials: S
authors.lastname: Törnroth
authors.forename: Bernadette
authors.initials: B
authors.lastname: Byrne
authors.forename: So
authors.initials: S
authors.lastname: Iwata
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D020134:Catalytic Domain; D002462:Cell Membrane / Q000201:enzymology; D018360:Crystallography, X-Ray; D004579:Electron Transport; D004926:Escherichia coli / Q000201:enzymology*; D005560:Formate Dehydrogenases / Q000737:chemistry* / Q000378:metabolism; D005561:Formates / Q000378:metabolism; D006150:Guanine Nucleotides / Q000737:chemistry / Q000378:metabolism; D006860:Hydrogen Bonding; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism; D008564:Membrane Potentials; D008958:Models, Molecular; D009565:Nitrate Reductases / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D018892:Proton-Motive Force; D011522:Protons; D011622:Pterins / Q000737:chemistry / Q000378:metabolism; D024482:Vitamin K 2 / Q000737:chemistry / Q000378:metabolism
chemical_list: D005561:Formates; D006150:Guanine Nucleotides; D007506:Iron-Sulfur Proteins; D021122:Protein Subunits; D011522:Protons; D011622:Pterins; C030544:formic acid; D024482:Vitamin K 2; C063761:molybdopterin guanine dinucleotide; D005560:Formate Dehydrogenases; D009565:Nitrate Reductases