Determination of the Molecular Structures of Ferric Enterobactin and Ferric Enantioenterobactin Using Racemic Crystallography
Author(s)
Johnstone, Timothy; Nolan, Elizabeth Marie
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Enterobactin is a secondary metabolite produced by Enterobacteriaceae for acquiring iron, an essential metal nutrient. The biosynthesis and utilization of enterobactin permits many Gram-negative bacteria to thrive in environments where low soluble iron concentrations would otherwise preclude survival. Despite extensive work carried out on this celebrated molecule since its discovery over 40 years ago, the ferric enterobactin complex has eluded crystallographic structural characterization. We report the successful growth of single crystals containing ferric enterobactin using racemic crystallization, a method that involves cocrystallization of a chiral molecule with its mirror image. The structures of ferric enterobactin and ferric enantioenterobactin obtained in this work provide a definitive assignment of the stereochemistry at the metal center and reveal secondary coordination sphere interactions. The structures were employed in computational investigations of the interactions of these complexes with two enterobactin-binding proteins, which illuminate the influence of metal-centered chirality on these interactions. This work highlights the utility of small-molecule racemic crystallography for obtaining elusive structures of coordination complexes. Keywords: iron; crystallization; metals; crystal structure; molecular structure
Date issued
2017-09Department
Massachusetts Institute of Technology. Department of ChemistryJournal
Journal of the American Chemical Society
Publisher
American Chemical Society (ACS)
Citation
Johnstone, Timothy C., and Elizabeth M. Nolan. "Determination of the Molecular Structures of Ferric Enterobactin and Ferric Enantioenterobactin Using Racemic Crystallography." Journal of the American Chemical Society 139, 42 (September 2017): 15245-15250 © 2017 American Chemical Society
Version: Author's final manuscript
ISSN
0002-7863
1520-5126