9gwu
From Proteopedia
Crystal structure of sulfoquinovose-1-dehydrogenase from Pseudomonas Putida (sulfo-ED pathway)
Structural highlights
FunctionSQD_PSEPU Catalyzes the oxidation of sulfoquinovose to 6-deoxy-6-sulfo-D-glucono-1,5-lactone, with a strong preference for NAD(+) as the electron acceptor. Is involved in a degradation pathway of sulfoquinovose (SQ) that allows P.putida SQ1 to use SQ as the sole carbon and energy source for growth.[1] Publication Abstract from PubMedThe sulfosugar sulfoquinovose (SQ) is catabolized through the sulfoglycolytic Entner-Doudoroff pathway, beginning with the oxidation of SQ to sulfogluconolactone by SQ dehydrogenase. We present a comprehensive structural and kinetic characterization of Pseudomonas putida SQ dehydrogenase (PpSQDH). PpSQDH is a tetrameric enzyme belonging to the short-chain dehydrogenase/reductase (SDR) superfamily with a strong preference for NAD+ over NADP+. Kinetic analysis revealed a rapid equilibrium ordered mechanism in which the NAD+ cofactor is the first substrate to bind, and NADH is the last product to dissociate. Structural studies revealed a homotetrameric structure in solution and crystals, involving cross-subunit interactions in which the C-terminus residue (Gln260) inserts into the diagonally opposite subunit to form part of the second shell of residues lining the active site. Complexes of PpSQDH with SQ or NAD+ provide insight into the recognition of SQ and together with the kinetic analysis allow the proposal of a catalytic reaction mechanism. Our findings illuminate the mechanism of SQ degradation and the evolution of the SDR superfamily for organosulfonate catabolism. Structure, kinetics, and mechanism of Pseudomonas putida sulfoquinovose dehydrogenase, the first enzyme in the sulfoglycolytic Entner-Doudoroff pathway.,Burchill L, Sharma M, Soler NM, Goddard-Borger ED, Davies GJ, Williams SJ Biochem J. 2025 Jan 22;482(2):57-72. doi: 10.1042/BCJ20240605. PMID:39840830[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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