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Atomic resolution structure of cholesterol oxidase @ pH 9.0 (Streptomyces sp. SA-COO)Atomic resolution structure of cholesterol oxidase @ pH 9.0 (Streptomyces sp. SA-COO)
Structural highlights
FunctionCHOD_STRS0 Bifunctional enzyme that catalyzes the oxidation of the 3-beta-hydroxy group of cholesterol and the isomerization of the double bond of the resulting product. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHydrogen atoms are a vital component of enzyme structure and function. In recent years, atomic resolution crystallography (>or=1.2 A) has been successfully used to investigate the role of the hydrogen atom in enzymatic catalysis. Here, atomic resolution crystallography was used to study the effect of pH on cholesterol oxidase from Streptomyces sp., a flavoenzyme oxidoreductase. Crystallographic observations of the anionic oxidized flavin cofactor at basic pH are consistent with the UV-visible absorption profile of the enzyme and readily explain the reversible pH-dependent loss of oxidation activity. Furthermore, a hydrogen atom, positioned at an unusually short distance from the main chain carbonyl oxygen of Met122 at high pH, was observed, suggesting a previously unknown mechanism of cofactor stabilization. This study shows how a redox active site responds to changes in the enzyme's environment and how these changes are able to influence the mechanism of enzymatic catalysis. Atomic resolution crystallography reveals how changes in pH shape the protein microenvironment.,Lyubimov AY, Lario PI, Moustafa I, Vrielink A Nat Chem Biol. 2006 May;2(5):259-64. Epub 2006 Apr 9. PMID:16604066[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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