Unprecedented (μ-1,1-Peroxo)diferric Structure for the Ambiphilic Orange Peroxo Intermediate of the Nonheme N-Oxygenase CmlI.

ABSTRACT: The final step in the biosynthesis of the antibiotic chloramphenicol is the oxidation of an aryl-amine substrate to an aryl-nitro product catalyzed by the N-oxygenase CmlI in three two-electron steps. The CmlI active site contains a diiron cluster ligated by three histidine and four glutamate residues and activates dioxygen to perform its role in the biosynthetic pathway. It was previously shown that the active oxidant used by CmlI to facilitate this chemistry is a peroxo-diferric intermediate (CmlI^P). Spectroscopic characterization demonstrated that the peroxo binding geometry of CmlI^P is not consistent with the μ-1,2 mode commonly observed in nonheme diiron systems. Its geometry was tentatively assigned as μ-η²:η¹ based on comparison with reson

SUBMITTER: Jasniewski AJ 

PROVIDER: S-EPMC5568637 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature