Function and Regulatory Mechanism of a Two-Component Signal Transduction System cgtRS5 in Corynebacterium glutamicum.

The putative two-component system (TCS) CgtRS5, encoded by the ncgl2572-ncgl2573 gene cluster, plays a critical role in environmental adaptation in Corynebacterium glutamicum. Comparative transcriptomic analysis between the wild-type strain and a ΔcgtRS5 mutant revealed three upregulated and 107 downregulated genes in the mutant. Among these, genes involved in iron metabolism (ncgl1959), aromatic compound degradation (ncgl2320), and drug resistance (cssR) were significantly downregulated. Phenotypic assays demonstrated that the ΔcgtRS5 mutant exhibited impaired growth in media supplemented with the divalent form of iron (Fe²⁺) or the alkylating agent iodoacetamide (IAM), but showed no significant differences under benzoate, resorcinol, or antibiotic stress. These results suggest that CgtRS5 specifically regulates the stress response to iron and IAM in C. glutamicum, providing new insights into TCS-mediated regulatory mechanisms in this organism.