# Mechanistic studies of a bifurcating flavoprotein

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA RIVERSIDE · 2021 · $296,166

## Abstract

Project Summary
 Electron-transferring flavoproteins (ETFs) are a large and broadly distributed family of
electron carriers that play critical roles in a variety of metabolic processes, including b-oxidation of
fatty acids in humans. Defects in ETFs give rise to several specific disease states. A subset of the
ETF family constitute a recently discovered class of complex flavoproteins that catalyze the coupled
reduction of high- and low-potential electron acceptors using a median-potential electron donor in a
process referred to as electron bifurcation. An example of such a bifurcating ETF is the EtfABCX
system from Pyrobaculum aerophilum. This enzyme accepts reducing equivalents from NADH,
passing the reducing equivalents on to the high-potential menaquinone and the low-potential iron-
sulfur protein ferredoxin in a manner that is overall thermodynamically favorable. The proposed
work will examine in detail the kinetics of electron bifurcation as catalyzed by EtfABCX, critically
evaluating the involvement of protonation/deprotonation processes associated with the primary
electron transfer events.

## Key facts

- **NIH application ID:** 10201670
- **Project number:** 5R01GM135088-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA RIVERSIDE
- **Principal Investigator:** Russ Hille
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $296,166
- **Award type:** 5
- **Project period:** 2020-07-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10201670

## Citation

> US National Institutes of Health, RePORTER application 10201670, Mechanistic studies of a bifurcating flavoprotein (5R01GM135088-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10201670. Licensed CC0.

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