Structural highlights
Publication Abstract from PubMedQuinone 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 zeta-crystallin-like QOR Zta1 from Saccharomycescerevisiae in apo-form at 2.00 A and complexed with NADPH at 1.59 A 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 zeta-crystallin-like QORs throughout evolution. Structural insights into the cofactor-assisted substrate recognition of yeast quinone oxidoreductase Zta1.,Guo PC, Ma XX, Bao ZZ, Ma JD, Chen Y, Zhou CZ J Struct Biol. 2011 Oct;176(1):112-8. Epub 2011 Jul 26. PMID:21820057[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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