The regulatory role of histidine kinase in modulating nucleoside metabolites in Streptomyces noursei CK-15

Histidine kinase (HK), a vital component of the two-component system (TCS), regulates the synthesis of secondary metabolites and is integral to key processes related to the growth and environmental adaptation of Streptomyces . The SHK gene may govern the manufacture of the nucleoside-type secondary metabolites Toyocamycin and Wuyiencin. This study generated a histidine kinase overexpression mutant strain ( S. noursei oSHK ) exploiting Δ toyG transcription data. This mutant strain was seen to suppress the growth of the CK-15 strain, resulting in a 25.94% reduction in Wuyiencin levels and a 17.64% decrease in Toyocamycin levels, while also decreasing spore formation and hyphal development rate. The SHK gene demonstrates reduced efficacy against bacteria and compromised nitrogen use. These findings suggest a detrimental regulatory influence of the SHK gene on strain viability and secondary metabolite synthesis in S. noursei CK-15, and this study provides theoretical justification for the modification of high-yielding Wuyiencin strains.