title: Structural insights into the cofactor-assisted substrate recognition of yeast quinone oxidoreductase Zta1.
abstract: Quinone oxidoreductase (QOR EC1.6.5.5) catalyzes the reduction of quinone to hydroxyquinone using NADPH as a cofactor. Here we present the crystal structure of the ζ-crystallin-like QOR Zta1 from Saccharomycescerevisiae in apo-form at 2.00 Å and complexed with NADPH at 1.59 Å resolution. Zta1 forms a homodimer, with each subunit containing a catalytic and a cofactor-binding domain. Upon NADPH binding to the interdomain cleft, the two domains shift towards each other, producing a better fit for NADPH, and tightening substrate binding. Computational simulation combined with site-directed mutagenesis and enzymatic activity analysis defined a potential quinone-binding site that determines the stringent substrate specificity. Moreover, multiple-sequence alignment and kinetics assays implied that a single-residue change from Arg in lower organisms to Gly in vertebrates possibly resulted in elevation of enzymatic activity of ζ-crystallin-like QORs throughout evolution.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei Anhui 230027, People's Republic of China.
authors.forename: Peng-Chao
authors.initials: PC
authors.lastname: Guo
authors.forename: Xiao-Xiao
authors.initials: XX
authors.lastname: Ma
authors.forename: Zhang-Zhi
authors.initials: ZZ
authors.lastname: Bao
authors.forename: Jin-Di
authors.initials: JD
authors.lastname: Ma
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Chen
authors.forename: Cong-Zhao
authors.initials: CZ
authors.lastname: Zhou
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D003067:Coenzymes; D003198:Computer Simulation; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D057075:Enzyme Assays; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D009249:NADP / Q000737:chemistry; D011485:Protein Binding; D011808:Quinone Reductases / Q000737:chemistry* / Q000235:genetics; D011809:Quinones / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: D003067:Coenzymes; D011809:Quinones; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D009249:NADP; C568900:Zta1 protein, S cerevisiae; D011808:Quinone Reductases