title: Converting the NiFeS carbon monoxide dehydrogenase to a hydrogenase and a hydroxylamine reductase.
abstract: Substitution of one amino acid for another at the active site of an enzyme usually diminishes or eliminates the activity of the enzyme. In some cases, however, the specificity of the enzyme is changed. In this study, we report that the changing of a metal ligand at the active site of the NiFeS-containing carbon monoxide dehydrogenase (CODH) converts the enzyme to a hydrogenase or a hydroxylamine reductase. CODH with alanine substituted for Cys(531) exhibits substantial uptake hydrogenase activity, and this activity is enhanced by treatment with CO. CODH with valine substituted for His(265) exhibits hydroxylamine reductase activity. Both Cys(531) and His(265) are ligands to the active-site cluster of CODH. Further, CODH with Fe substituted for Ni at the active site acquires hydroxylamine reductase activity.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA.
authors.forename: Jongyun
authors.initials: J
authors.lastname: Heo
authors.forename: Marcus T
authors.initials: MT
authors.lastname: Wolfe
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Staples
authors.forename: Paul W
authors.initials: PW
authors.lastname: Ludden
mesh_terms: D000114:Acetylene; D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D003486:Cyanides; D006864:Hydrogenase / Q000235:genetics / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D012247:Rhodospirillum rubrum / Q000201:enzymology* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D003486:Cyanides; D007506:Iron-Sulfur Proteins; D009097:Multienzyme Complexes; C075199:prismane protein, Desulfovibrio vulgaris; D010088:Oxidoreductases; D006864:Hydrogenase; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase; C021402:hydroxylamine reductase; D000114:Acetylene