Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center.

ABSTRACT: Carotenoid cleavage oxygenases (CCOs) are non-heme iron enzymes that catalyze scission of alkene groups in carotenoids and stilbenoids to form biologically important products. CCOs possess a rare four-His iron center whose resting-state structure and interaction with substrates are incompletely understood. Here, we address this knowledge gap through a comprehensive structural and spectroscopic study of three phyletically diverse CCOs. The crystal structure of a fungal stilbenoid-cleaving CCO, CAO1, reveals strong similarity between its iron center and those of carotenoid-cleaving CCOs, but with a markedly different substrate-binding cleft. These enzymes all possess a five-coordinate high-spin Fe(II) center with resting-state Fe-His bond lengths of ∼2.15 Å. This ligand set generates an iron

SUBMITTER: Sui X 

PROVIDER: S-EPMC5541372 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature