화학공학소재연구정보센터
Applied Microbiology and Biotechnology, Vol.99, No.20, 8629-8641, 2015
Proteomic insights into metabolic adaptation to deletion of metE in Saccharopolyspora spinosa
Saccharopolyspora spinosa can produce spinosad as a major secondary metabolite, which is an environmentally friendly agent for insect control. Cobalamin-independent methionine synthase (MetE) is an important enzyme in methionine biosynthesis, and this enzyme is probably closely related to spinosad production. In this study, its corresponding gene metE was inactivated, which resulted in a rapid growth and glucose utilisation rate and almost loss of spinosad production. A label-free quantitative proteomics-based approach was employed to obtain insights into the mechanism by which the metabolic network adapts to the absence of MetE. A total of 1440 proteins were detected from wild-type and Delta metE mutant strains at three time points: stationary phase of Delta metE mutant strain (S1(Delta metE) , 67 h), first stationary phase of wild-type strain (S1(WT), 67 h) and second stationary phase of wild-type strain (S2(WT), 100 h). Protein expression patterns were determined using an exponentially modified protein abundance index (emPAI) and analysed by comparing S1(Delta metE) /S1(WT) and S1(Delta metE) /S2(WT). Results showed that differentially expressed enzymes were mainly involved in primary metabolism and genetic information processing. This study demonstrated that the role of MetE is not restricted to methionine biosynthesis but rather is involved in global metabolic regulation in S. spinosa.