OseR, a bacterial redox sensor, regulates ergothioneine uptake via a Cys thiol switch, enhancing oxidative stress resistance and virulence.

ABSTRACT: Ergothioneine (ET), a low-molecular-weight (LMW) thiol, serves as a potent antioxidant. While only a limited number of Actinomycetes and fungi can synthesize ET, most microorganisms acquire it from external sources. Recently, a microbial ET transporter system (EtUV) was identified in Helicobacter pylori and Streptococcus pneumoniae, but the regulatory mechanisms controlling EtUV in bacteria remain unknown. In this study, we identified and characterized OseR, a novel MarR family repressor in Streptococcus suis, a significant pathogen causing systemic diseases such as septicemia and meningitis in pigs and humans. We demonstrated that OseR senses oxidative stress through a thiol switch at Cys35, which regulates the ET transport system EtUV. Under oxidative stress, OseR dissociates from the pr

SUBMITTER: Zhu X 

PROVIDER: S-EPMC12341727 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature