Molecular Insight into Substrate Recognition and Catalysis of Baeyer鈥揤illiger Monooxygenase MtmOIV, the Key Frame-Modifying Enzyme in the Biosynthesis of Anticancer Agent Mithramycin

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• 作者：Mary A. Bosserman ; Theresa Downey ; Nicholas Noinaj ; Susan K. Buchanan ; J眉rgen Rohr
• 刊名：ACS Chemical Biology
• 出版年：2013
• 出版时间：November 15, 2013
• 年：2013
• 卷：8
• 期：11
• 页码：2466-2477
• 全文大小：769K
• 年卷期：v.8,no.11(November 15, 2013)
• ISSN：1554-8937

文摘

Baeyer鈥揤illiger monooxygenases (BVMOs) have been shown to play key roles for the biosynthesis of important natural products. MtmOIV, a homodimeric FAD- and NADPH-dependent BVMO, catalyzes the key frame-modifying steps of the mithramycin biosynthetic pathway, including an oxidative C鈥揅 bond cleavage, by converting its natural substrate premithramycin B into mithramycin DK, the immediate precursor of mithramycin. The drastically improved protein structure of MtmOIV along with the high-resolution structure of MtmOIV in complex with its natural substrate premithramycin B are reported here, revealing previously undetected key residues that are important for substrate recognition and catalysis. Kinetic analyses of selected mutants allowed us to probe the substrate binding pocket of MtmOIV and also to discover the putative NADPH binding site. This is the first substrate-bound structure of MtmOIV providing new insights into substrate recognition and catalysis, which paves the way for the future design of a tailored enzyme for the chemo-enzymatic preparation of novel mithramycin analogues.