Iterative Catalysis in the Biosynthesis of Mitochondrial Complex II Inhibitors Harzianopyridone and Atpenin B
Undramaa Bat-Erdene, Daiki Kanayama, Dan Tan, William C. Turner, K. N. Houk, Masao Ōhashi, Yi Tang
Abstract
The pentasubstituted pyridine natural products harzianopyridone and atpenins are potent inhibitors of mitochondrial complex II. We identified the pathways of these compounds from their fungal producers and uncovered that the biosynthetic steps require multiple iterative enzymes. In particular, a methyltransferase and a flavin-dependent monooxygenase are used iteratively to introduce C5 and C6 methoxy groups. The pathway unexpectedly requires the installation and removal of an N-methoxy group, which is proposed to be a directing group that tunes the reactivity of the pyridone ring, possibly through the alpha effect.
Topics & Concepts
ChemistryBiosynthesisEnzymeStereochemistryFlavin groupPyridineMethyltransferaseMonooxygenaseReactivity (psychology)BiochemistryCatalysisCombinatorial chemistryOrganic chemistryCytochrome P450MethylationGeneMedicinePathologyAlternative medicineMicrobial Natural Products and BiosynthesisSynthetic Organic Chemistry MethodsChemical synthesis and alkaloids