The Function Of Oxidation Sensor ILFT In Mycobacterium Tuberculosis

Oxidative stress is a common environmental factor faced by pathogens when they invade the host.Mycobacterium tuberculosis,pathogen of human tuberculosis,takes several measures to deal with this environmental stress for surviving in the macrophage.However,the regulation mechanism on how Mycobacterium tuberculosis cope with this stress remains unknown.In this study,we prove IlfT a new oxidation sensor of Mycobacterium tuberculosis through analyzing its function.The results are as follows:1.IlfT was detected to interact with the promoter of ila by bacterial one-hybrid and EMSA assays,and direct repetitive sequence(CGAAATACGGA)was identified to be binding motif by footprint experiments.2.DNA binding activity of IlfT was hurted when the protein was dealed with H2O2,and Cys42 and Cys167 were the key amino acid residue responsing H2O2.3.IlfT was further proved to be negative transcription factor which regulates self-expression and a redox gene by the P-galactosidase activities assay.4.Mycobacterium tuberculosis with overespressing ilfT is less sensitive to H2O2 than Wild-type strain.In summary,IlfT,a new oxidation-sensing transcriptional factor in Mycobacterium tuberculosis,was found in this study.This transcriptional factor plays significant role on Mycobacterium tuberculosis facing oxidative stress by regulating redox gene.The results facilicate us to know the antioxidant mechanism in Mycobacterium tuberculosis.