Protein‐DNA Interactome of the OxyR Oxidative‐Stress Transcription Factors in Aliivibrio fischeri

Abstract

Transcription factors (TFs) are sequence‐specific DNA‐binding proteins that dictate cell function by controlling selective usage of genomic information. One of the largest prokaryotic family of TFs is the LysR type transcriptional regulators (LTTRs). These TFs tend to regulate a diverse set of genes involved in virulence, metabolism, quorum sensing, and oxidative stress. Hydrogen peroxide (H2O2) is a well‐known cell damaging agent, which can lead to oxidative stress, disease, and important beneficial signaling roles. OxyR is a transcription factor with an N‐terminal DNA‐binding helix‐turn‐helix motif and a C‐terminal co‐inducer‐binding domain, that is involved in the defense mechanism against hydrogen peroxide‐induced oxidative stress. Although, different OxyR proteins share functional and sequence similarities across different bacterial species, they respond differently to hydrogen peroxide. The symbiotic relationship between Euprymna scolopes and Aliivibrio fischeri is dependent on the initial colonization survival of the bacteria in an environment rich reactive oxygen species. It has been documented that A. fischeri’s genome encodes two OxyR genes, OxyR1 and OxyR2. Studying OxyR1 and OxyR2 protein‐DNA interactomes will allow us to identify key differences and their possible roles in oxidative stress responses. Currently, we have over‐expressed and purified the full‐length OxyR1 and OxyR2 and their DNA binding domain. Protein functionality has been tested by Electric Mobility Shift Assay (EMSA), and High‐Throughput Systematic Evolution of Ligands by Exponential Enrichment (HT‐SELEX) will be used to determine the protein‐DNA interactomes of the OxyR1 and OxyR2. Genomic targets of OxyR1 and OxyR2 will be bioinformatically predicted once the DNA‐binding specificities are established.Support or Funding InformationNational Institutes of Health SC1GM127231.