Determining the Role of the CooA Heme and its Environment in Carbon Monoxide Specific Sensing

Level of Education of Students Involved


Faculty Sponsor

Dr. Robert Clark


Arts and Sciences



ORCID Identifier(s)

Nicole Norfolk 0000-0001-9731-920X; Burke Niego 0000-0003-0516-2386; Antigone Wilson 0000-0001-5611-8866; Alexa Lederhaus 0009-0008-5680-3036

Presentation Type

Poster Presentation

Symposium Date

Spring 4-27-2023


CooA is a protein found in Rhodospirillum rubrum (Rr) and Carboxydothermus hydrogenoformans (Ch) and is both a carbon monoxide (CO) sensor and transcription factor. When CO binds to a CooA heme, the protein undergoes a conformational change that enables it to bind to DNA. The broader goal of this research is to obtain a mechanistic understanding of how the CooA heme iron, along with amino acids that are attached to that iron, enable CooA to act as a CO-specific sensor. Experiments have been performed involving the substitution of the heme center for other transition metals, specifically manganese, to determine the chemical or physical changes the protein undergoes. This project was evaluated using electronic absorbance (UV-Visible) spectroscopy to study the CooA iron/metal bonding environment and fluorescence spectroscopy to study CooA DNA binding. Preliminary results suggest the metal complex coordination number and porphyrin distortion influence the ability of the protein to bind DNA for the Ch homolog when the terminal, distal amino acid side chain is unbound from the metal center.

This document is currently not available here.