Functional Study Of Aerial Mycelium-related Protein SCO4184 Of Streptomyces Coelicolor

Streptomyces is an important industrial strain that produces some natural secondary metabolites such as antibiotics.Its morphological differentiation and secondary metabolic processes have always been the focus of research.With the advancement of genome sequencing technology and protein-related technologies,the functions and complex regulatory mechanisms of many proteins in the life cycle of Streptomyces have been studied,which is of great help to better explore the industrial value of Streptomyces.The research team conducted a preliminary study on the function and regulatory mechanism of the sporulation associated protein SCO4114.During the research process,we found that there are some literature reporting that SCO4114 can restore the phenotype of SCO4184-deficient strains related to aerial mycelium formation,but the relationship between the two proteins and the function of SCO4184 are not yet clear.Therefore,this article mainly studies the function of SCO4184.At first,we constructed sco4184 knockout strain and overexpression strain by using CRISPR gene editing technology and pKC1139 high-copy plasmid.Then,by observing the phenotype of each mutant strain on different media and measuring the growth curve and production curve of the ?sco4184 strain,it was found that the ?sco4184 strain was bald,the growth rate was accelerated,and there was little actinomycin(ACT)and undecylerythromycin(RED).To observe the morphology of ?sco4184 strain by scanning electronmicroscopy(SEM),it was showed that the cells were elliptical rods,and there were still apical growth sites,which did not show normal morphological differentiation.Furthermore,the result of surface plasmon resonance(SPR)revealed that SCO4114 and SCO4184 can be directly combined.In addition,it has been proved through the inhibited circle of lysozyme and the lysozyme hydrolysis resistance test of cell wall extraction that the cell wall of ?sco4184strain is less sensitive to lysozyme and produces lysozyme resistance.However,by detecting the cell wall composition of strain ?sco4184,it was found that during the synthesis of peptidoglycan,some peptide amino acid modifications were blocked or the sugar chain backbone was de-modified,resulting in enhanced anti-lysozyme hydrolysis ability,the detected molecular weight of peptidoglycan was larger,and fewer types of ion fragments.In summary,this article has studied the function of SCO4184 through the above experiments and showed that SCO4184 can affect the cell wall and cell division of Streptomyces coelicolor A3(2),thus affecting its sporulation and secondary metabolic processes.