Effects of lytS-L on the primary metabolism and butenyl-spinosyn biosynthesis in Saccharopolyspora pogona

The LytTR family two-component system widely exists in bacterial cells and plays an important role in metabolic regulation. The lytS-L gene that encodes for a LytTR family sensor kinase was knocked out to study its influence on the growth, phenotype, and the biosynthesis of the insecticidal polyketide butenyl-spinosyn in Saccharopolyspora pogona NRRL 30141 (S. pogona). High performance liquid chromatography (HPLC) results showed that the butenyl-spinosyn yield of the lytS-L knockout mutant decreased by 58.9% compared with that of the parental strain. This is manifested by a weak toxicity of the mutant against the insect Helicoverpa assulta (H. armigera). Comparative proteomic analysis revealed the expression characteristics of the proteins in S. pogona and S. pogona-ΔlytS-L: a total of 14 proteins involved in energy metabolism were down-regulated, 9 proteins related to carbon metabolism such as glycolysis, and tricarboxylic acid cycle (TCA) were up-regulated, while 13 proteins involved in the biosynthesis of butenyl-spinosyn were down-regulated (fold change >1.2 or< 0.83). The qRT-PCR (Quantitative Real-time PCR) analysis illustrated that the changes in the expression levels of transcription and translation of the identified genes were consistent. This study explores the function of the two-component system of the LytTR family in S. pogona and shows that the lytS-L gene has an important influence on regulating primary metabolism and butenyl-spinosyn biosynthesis of S. pogona.