文章基本信息

标题：Mechanism of action of a flavin-containing monooxygenase
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作者：Subramaniam Eswaramoorthy ; Jeffrey B. Bonanno ; Stephen K. Burley 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2006
卷号：103
期号：26
页码：9832-9837
DOI：10.1073/pnas.0602398103
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Elimination of nonnutritional and insoluble compounds is a critical task for any living organism. Flavin-containing monooxygenases (FMOs) attach an oxygen atom to the insoluble nucleophilic compounds to increase solubility and thereby increase excretion. Here we analyze the functional mechanism of FMO from Schizosaccharomyces pombe using the crystal structures of the wild type and protein-cofactor and protein-substrate complexes. The structure of the wild-type FMO revealed that the prosthetic group FAD is an integral part of the protein. FMO needs NADPH as a cofactor in addition to the prosthetic group for its catalytic activity. Structures of the protein-cofactor and protein-substrate complexes provide insights into mechanism of action. We propose that FMOs exist in the cell as a complex with a reduced form of the prosthetic group and NADPH cofactor, readying them to act on substrates. The 4{alpha}-hydroperoxyflavin form of the prosthetic group represents a transient intermediate of the monooxygenation process. The oxygenated and reduced forms of the prosthetic group help stabilize interactions with cofactor and substrate alternately to permit continuous enzyme turnover.
关键词：three-dimensional-structure ; xenobiotics ; methimazole