title: Ni-Zn-[Fe4-S4] and Ni-Ni-[Fe4-S4] clusters in closed and open subunits of acetyl-CoA synthase/carbon monoxide dehydrogenase.
abstract: The crystal structure of the tetrameric alpha2beta2 acetyl-coenzyme A synthase/carbon monoxide dehydrogenase from Moorella thermoacetica has been solved at 1.9 A resolution. Surprisingly, the two alpha subunits display different (open and closed) conformations. Furthermore, X-ray data collected from crystals near the absorption edges of several metal ions indicate that the closed form contains one Zn and one Ni at its active site metal cluster (A-cluster) in the alpha subunit, whereas the open form has two Ni ions at the corresponding positions. Alternative metal contents at the active site have been observed in a recent structure of the same protein in which A-clusters contained one Cu and one Ni, and in reconstitution studies of a recombinant apo form of a related acetyl-CoA synthase. On the basis of our observations along with previously reported data, we postulate that only the A-clusters containing two Ni ions are catalytically active.
authors.affiliation: Laboratoire de Cristallographie et Cristallogenèse des Protéines, Institut de Biologie Structurale 'Jean-Pierre Ebel', CEA, UJF, CNRS, 41, rue Jules Horowitz, 38027, Grenoble Cedex 1, France.
authors.forename: Claudine
authors.initials: C
authors.lastname: Darnault
authors.forename: Anne
authors.initials: A
authors.lastname: Volbeda
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Kim
authors.forename: Pierre
authors.initials: P
authors.lastname: Legrand
authors.forename: Xavier
authors.initials: X
authors.lastname: Vernède
authors.forename: Paul A
authors.initials: PA
authors.lastname: Lindahl
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fontecilla-Camps
mesh_terms: D000106:Acetate-CoA Ligase / Q000737:chemistry* / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000096:biosynthesis; D000445:Aldehyde Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D020134:Catalytic Domain; D003013:Clostridium / Q000201:enzymology; D018360:Crystallography, X-Ray; D007501:Iron / Q000737:chemistry; D008954:Models, Biological; D008958:Models, Molecular; D015394:Molecular Structure; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism; D009532:Nickel / Q000737:chemistry; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D055672:Static Electricity; D013455:Sulfur / Q000737:chemistry; D015032:Zinc / Q000737:chemistry
chemical_list: D009097:Multienzyme Complexes; D021122:Protein Subunits; D013455:Sulfur; D000105:Acetyl Coenzyme A; D009532:Nickel; D007501:Iron; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase; D000106:Acetate-CoA Ligase; D015032:Zinc