Reactive sulfur species mediated persulfidation cascade regulation mechanism of novel transcription factor SscRAc in extremophile Acidithiobacillus caldus under extreme copper stress.

ABSTRACT: Severe environmental conditions enhance the resilience of biomining microorganisms to elevated metal ion concentrations. The mechanism of how biomining microorganisms resist metal ions is poorly understood. We identified a novel reactive sulfur species (RSS)-sensitive MarR family transcription factor (SscRAc) in Acidithiobacillus caldus by persulfidation proteomics and observed increase in RSS and protein persulfidation levels under 250 mM Cu2+ stress. The deletion of sscRAc gene via CRISPR-Cas9 and conjugative transfer technology enhanced copper sensitivity in A. caldus. ChIP-seq/qRT-PCR revealed that SscRAc regulates copper detoxification by blocking efflux pumps and stimulating RSS metabolism. LC-MS/MS analysis revealed that both Cys74 and Cys78 in SscRAc interact with RSS and undergo p

SUBMITTER: Huo X 

PROVIDER: S-EPMC12455602 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature