SfnR2 Regulates Dimethyl Sulfide-Related Utilization in Pseudomonas aeruginosa PAO1

Abstract

Dimethyl sulfide (DMS) is an important environmental source of sulfur, carbon, and/or energy for microorganisms. For various bacteria, including Pseudomonas , Xanthomonas , and Azotobacter , DMS utilization is thought to be controlled by the transcriptional regulator SfnR. Adding more complexity, some bacteria, such as Acinetobacter baumannii , Enterobacter cloacae , and Pseudomonas aeruginosa , possess two, nonidentical SfnR proteins. In this study, we demonstrate that SfnR2 and not SfnR1 is the principal regulator of DMS metabolism in P. aeruginosa PAO1. Results suggest that SfnR1 has a supportive but nonessential role in the positive regulation of genes required for DMS utilization. This study not only enhances our understanding of SfnR regulation but, importantly, also provides a framework for addressing gene regulation through dual SfnR proteins in other bacteria.