No Bridge between Us: EXAFS and Computations Confirm Two Distant Iron Ions Comprise the Active Site of Alkane Monooxygenase (AlkB).

ABSTRACT: Alkane monooxygenase (AlkB) is the dominant enzyme that catalyzes the oxidation of liquid alkanes in the environment. Two recent structural models derived from cryo-electron microscopy (cryo-EM) reveal an unusual active site: a histidine-rich center that binds two iron ions without a bridging ligand. To ensure that potential photoreduction and radiation damage are not responsible for the absence of a bridging ligand in the cryo-EM structures, spectroscopic methods are needed. We present the results of extended X-ray absorption fine structure (EXAFS) experiments collected under conditions where photodamage was avoided. Careful data analysis reveals an active site structure consistent with the cryo-EM structures in which the two iron ions are ligated by nine histidines and separated by at le

SUBMITTER: Reinhardt CR 

PROVIDER: S-EPMC11753938 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature