Spectroscopy and DFT Calculations of a Flavo-diiron Enzyme Implicate New Diiron Site Structures.

ABSTRACT: Flavo-diiron proteins (FDPs) are non-heme iron containing enzymes that are widespread in anaerobic bacteria, archaea, and protozoa, serving as the terminal components to dioxygen and nitric oxide reductive scavenging pathways in these organisms. FDPs contain a dinuclear iron active site similar to that in hemerythrin, ribonucleotide reductase, and methane monooxygenase, all of which can bind NO and O₂. However, only FDP competently turns over NO to N₂O. Here, EPR and Mössbauer spectroscopies allow electronic characterization of the diferric and diferrous species of FDP. The exchange-coupling constant J (H_ex = JS₁·S₂) was found to increase from +20 cm^-1 to +32 cm^-1 upon reduction of the diferric to the diferrous sp

SUBMITTER: Weitz AC 

PROVIDER: S-EPMC5898632 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature