Molecular Basis of Iterative C–H Oxidation by TamI, a Multifunctional P450 Monooxygenase from the Tirandamycin Biosynthetic Pathway
| Autor: | Marc Garcia-Borràs, Larissa M. Podust, Kinshuk Raj Srivastava, Yogan Khatri, Rachel M. Martini, Kersti Caddell Haatveit, David H. Sherman, Rosa V. Espinoza, Kendall N. Houk, Sean A. Newmister |
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| Rok vydání: | 2020 |
| Předmět: |
natural product
cytochrome P450 Stereochemistry Tirandamycin 010402 general chemistry 01 natural sciences antibiotics Article Catalysis Inorganic Chemistry Hydroxylation chemistry.chemical_compound Molecular recognition Biosynthesis Molecule Reactivity (chemistry) chemistry.chemical_classification Natural product 010405 organic chemistry Organic Chemistry General Chemistry Chemical Engineering Polyene molecular dynamics Enzyme structure enzyme structure 0104 chemical sciences Enzyme chemistry Biocatalysis Generic health relevance biosynthesis |
| Zdroj: | ACS Catal ACS catalysis, vol 10, iss 22 |
| Popis: | Biocatalysis offers an expanding and powerful strategy to construct and diversify complex molecules by C-H bond functionalization. Due to their high selectivity, enzymes have become an essential tool for C-H bond functionalization and offer complementary reactivity to small-molecule catalysts. Hemoproteins, particularly cytochromes P450, have proven effective for selective oxidation of unactivated C-H bonds. Previously, we reported the in vitro characterization of an oxidative tailoring cascade in which TamI, a multifunctional P450 functions co-dependently with the TamL flavoprotein to catalyze regio- and stereoselective hydroxylations and epoxidation to yield tirandamycin A and tirandamycin B. TamI follows a defined order including 1) C10 hydroxylation, 2) C11/C12 epoxidation, and 3) C18 hydroxylation. Here we present a structural, biochemical, and computational investigation of TamI to understand the molecular basis of its substrate binding, diverse reactivity, and specific reaction sequence. The crystal structure of TamI in complex with tirandamycin C together with molecular dynamics simulations and targeted mutagenesis suggest that hydrophobic interactions with the polyene chain of its natural substrate are critical for molecular recognition. QM/MM calculations and molecular dynamics simulations of TamI with variant substrates provided detailed information on the molecular basis of sequential reactivity, and pattern of regio- and stereo-selectivity in catalyzing the three-step oxidative cascade. |
| Databáze: | OpenAIRE |
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