Label-free proteomic dissection on dptP-deletion mutant uncovers dptP involvement in strain growth and daptomycin tolerance of Streptomyces roseosporus.

Daptomycin (DAP) is a novel microbial lipopeptide antibiotic synthesized by the DAP biosynthetic gene cluster dpt of Streptomyces roseosporus (S. roseosporus). DptP gene locates upstream of dpt and confers DAP resistance to Streptomyces ambofaciens (S. ambofaciens). So far, the biological functions of dptP gene for S. roseosporus growth are still completely uncovered. We performed label-free quantification proteomic dissections with loss- and gain-of-function experiments to decipher dptP-involved functions. Deletion of dptP gene activated energy metabolism and metabolism of secondary metabolites pathways and enhanced the transcription levels and protein abundance of key members of the dpt cluster. Whereas dptP deletion inhibited transport/signal transduction and drug resistance pathways and protein abundance of cell division-relative proteins, subsequently decreased mycelia cell growth rate. S. roseosporus strain with dptP deletion was more sensitive to DAP treatment compared to the wild type. In contrast, overexpression of dptP gene decreased transcription levels of DAP biosynthetic genes and enhanced growth rate of Streptomcyes strain upon elevated culture temperature and DAP supplementation. Taken together, dptP gene contributes to Streptomcyes primary growth under elevated temperature and DAP treatment, whereas it plays negative roles on metabolism of secondary metabolites and transcription of DAP biosynthetic genes.