Study On The Function And Regulation Mechanism Of RNA Binding Protein RsmA RsmE And RsmI In Pseudomonas Fluorescens

Gac/Rsm cascade controlling system is widely founded in gram-negative bacteria.As the downstream component of Gac/Rsm system,Rsm RNA binging proteins(RBPs)directly regulate multiple biological processes such as motility,biofilm formation,the production and secretion of virulence,the synthesis of secondary metabolism.Different types of pseusomonas have evolved various Rsm RBPS.In this study,the effects of RBPs RsmA,RsmE,RsmI on the total protein expression level of Pseudomonas fluorescens 2P24 we investigated using label free quantitative proteomics.The yield changes of secondary metabolites mupirocin,2,4-diacetylphloroglucinol and hydrogen cyanide in the gene mutant strains of these three RBPs was tested.And the molecular mechanism of RsmE in regulating the synthesis of mupirocin was explored preliminarily.The results revealed that these three RBPs had different effects on different secondary metabolites,while RsmE had the greatest effect on bacteria.In addition,RsmE may indirectly regulate the production of mupirocin by repressing mupI,the gene responsible for synthesis of N-acyl homoserine lactones types quorum sensing signal molecules.In conclusion,we found that RBPs RsmA,RsmE and RsmI have functional differentiated based on the proteomics data and phenotype validation.