The structure of SpnF, a standalone enzyme that catalyzes [4 + 2] cycloaddition
Christopher D Fage1, Eta A Isiorho1, Yungnan Liu2
1Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA.
Abstract:
In the biosynthetic pathway of the spinosyn insecticides, the tailoring enzyme SpnF performs a [4 + 2] cycloaddition on a 22-membered macrolactone to forge an embedded cyclohexene ring. To learn more about this reaction, which could potentially proceed through a Diels-Alder mechanism, we determined the 1.50-Å-resolution crystal structure of SpnF bound to S-adenosylhomocysteine. This sets the stage for advanced experimental and computational studies to determine the precise mechanism of SpnF-mediated cyclization.
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