# Structural Studies of Alternating-site Reactivity in Nitrogenase-like Oxidoreductases

> **NIH NIH F32** · CORNELL UNIVERSITY · 2021 · $66,390

## Abstract

Project Summary / Abstract
Nature uses protein allostery to control long-range electron flow in chemical reactions essential
for life. Metals and metal-clusters are often key components facilitating this electron transfer. A
known allosteric method for gating electron flow in metalloenzymes is alternating-site reactivity,
wherein reactivity switches from one half of the enzyme to the other upon conformational
changes. Oxidoreductases, with a core α2β2 heterotetrameric structure, are iron-sulfur cluster
metalloenzymes that employ alternating-site reactivity and can serve as an invaluable model
system to define the structural motifs and mechanisms required for metalloenzyme allosteric
regulation. In line with the NIH NIGMS Pharmacology, Physiology, and Biochemical Chemistry
mission of “improving molecular level understanding of fundamental biological processes and
discovering approaches to their control”, we propose to study two such oxidoreductases, the
nitrogenase-like dark-operative chlorophyllide oxidoreductase (DPOR) and chlorophyllide
oxidoreductase (COR), to identify how long-ranged correlated motions contribute to alternating-
site reactivity using structural biology tools. We will employ electron microscopy and small-angle
X-ray scattering techniques to examine enzyme conformational intermediates with asymmetrical
conformations.

## Key facts

- **NIH application ID:** 10157289
- **Project number:** 1F32GM140763-01
- **Recipient organization:** CORNELL UNIVERSITY
- **Principal Investigator:** Amanda Byer
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $66,390
- **Award type:** 1
- **Project period:** 2021-04-15 → 2024-04-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10157289

## Citation

> US National Institutes of Health, RePORTER application 10157289, Structural Studies of Alternating-site Reactivity in Nitrogenase-like Oxidoreductases (1F32GM140763-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10157289. Licensed CC0.

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