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Nitrogen Fixation by Nitrogenase


EMSL Project ID
60812

Abstract

The bacterial catalyst for N2 fixation is a multi-subunit metalloenzyme comprising two electron carrier Fe proteins and the MoFe protein core. This complex catalyzes the reduction of N2 to NH3 and H2, with electrons provided by the Fe protein upon adenosine triphosphate hydrolysis. Our continued investigation of mechanism of nitrogenase activation and N2 binding via quantum chemical studies, combined with biochemical assays from Seefeldt and ENDOR measurements by Hoffman, revealed key features of the nitrogenase catalytic mechanism. Our studies highlighted that the thermodynamics of binding and activation of N2 takes place at the E4 state, which is activated by the accumulation of 4[e-/H+], with the concomitant reductive elimination of H2. We propose to extend our previous combined experimental/computational investigations to further explore the electronic rearrangements upon electron and proton delivery to the catalytic cofactor and upon N2 activation and reduction.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2023-10-01
End Date
N/A
Status
Active

Team

Principal Investigator

Simone Raugei
Institution
Pacific Northwest National Laboratory

Co-Investigator(s)

Bojana Ginovska
Institution
Pacific Northwest National Laboratory

Team Members

Maureen Kitheka
Institution
Pacific Northwest National Laboratory

Brian Hoffman
Institution
Northwestern University

Lance Seefeldt
Institution
Utah State University