Implication of a Key Region of Six <i>Bacillus cereus</i> Genes Involved in Siroheme Synthesis, Nitrite Reductase Production and Iron Cluster Repair in the Bacterial Response to Nitric Oxide Stress

• Main Authors: Constance Porrini, Cyprien Guérin, Seav-Ly Tran, Rozenn Dervyn, Pierre Nicolas, Nalini Ramarao
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Bacillus cereus</i>; nitric oxide; iron cluster repair; transcriptomic
• Online Access: https://www.mdpi.com/1422-0067/22/10/5079

Bacterial response to nitric oxide (NO) is of major importance for bacterial survival. NO stress is a main actor of the eukaryotic immune response and several pathogenic bacteria have developed means for detoxification and repair of the damages caused by NO. However, bacterial mechanisms of NO resistance by Gram-positive bacteria are poorly described. In the opportunistic foodborne pathogen <i>Bacillus cereus</i>, genome sequence analyses did not identify homologs to known NO reductases and transcriptional regulators, such as NsrR, which orchestrate the response to NO of other pathogenic or non-pathogenic bacteria. Using a transcriptomic approach, we investigated the adaptation of <i>B. cereus</i> to NO stress. A cluster of 6 genes was identified to be strongly up-regulated in the early phase of the response. This cluster contains an iron-sulfur cluster repair enzyme, a nitrite reductase and three enzymes involved in siroheme biosynthesis. The expression pattern and close genetic localization suggest a functional link between these genes, which may play a pivotal role in the resistance of <i>B. cereus</i> to NO stress during infection.