Study On The Regulatory Protein Srpa Controlling Many Improtant Pathways Expression Of Pseudomonas Aeruginosa And The Mechanism Of Phage Infection

Phage has a necessary genetic equipment to ensure their invasion,replication and production.Some of these essential genes on the phage genome and the others is derived from the genes of the host bacteria.In this study,We constructed the Tn5G transposon library of Pseudomonas aeruginosa PAK-AR2,screened mutants resistant to phage K5,and identified the insertion site of Tn5G on the PAK-AR2 genome by reverse PCR.In this process,we screened a mutant strain with the same rate of adsorption,which was inserted into the gene as an unknown function gene on the genome of Pseudomonas aeruginosa.The gene encodes a small molecule protein of 84 amino acids.The bioinformatics analysis of the protein has a DNA-specific binding site as a possible transcriptional regulator.Gel blocking experiments confirmed that the binding protein binds to the upstream region of the phage genomic RNA polymerase gene from-201 to-183 sequence binding,binding phage RNA polymerase to promote the expression of RNA polymerase.Phage partial gene transcription requires RNA polymerase to complete the key genes such as phage DNA polymerase,major capsid protein,major substrate protein,and phosphodiester reductase.Thus,the phage infection process requires the protein and phage RNA polymerase to be involved.At the same time,by analyzing the transcriptomics data,the gene affected the transcription level of 820 genes on the genome of P.seudomonas aeruginosa,and differentially expressed genes were identified,and several important systems with significant influence were experimentally verified.The results showed that the type ? secretion system of the mutant decreased,and the effect protein secretion was reduced.V1 secretion system expression level,the bactericidal ability of E.coli was significantly enhanced.Mutant gene plays an important role in maintaining the motility of Pseudomonas aeruginosa.The cluster movement diameter of the mutant is much larger than that of the wild type strain.The expression of type ? fimbriae related gene of the mutant decreased,and the diameter of the movement was significantly smaller.At the same time,the gene promotes the formation of biofilm and inhibits the chemotaxis of bacteria,which plays an important role in adapting the bacteria to the environment.Mutant ribosomal expression level decreased,cell growth slowed down,coupled with significant changes in cell expression system,so that the expression of cytotoxic factors decreased,the ability to kill beautiful nematodes weakened.In summary,the small molecule protein is a global regulator of the genome of Pseudomonas aeruginosa,so we will encode the protein named srpA(Small regulator protein A).This gene not only plays an important role in phage infection,but also controls the expression of many important metabolic pathogens of Pseudomonas aeruginosa,plays an important role in the pathogenicity and environmental adaptability of Pseudomonas aeruginosa,the most promising drug target for bacterial infection.