The Pathogenic Mechanism Study Of A Protein In Mycobacterium Tuberculosis

Tuberculosis is a disease that has been discovered ever since the ancient times.Potentially efficacious drugs failed to reduce prevalence of infection by Mycobacterium tuberculosis in most areas of the world.It is rated as the second deficient infectious disease for high drug resistance,high mortality as well as low degradation rate.One way to prevent infection is to take Bacille Calmette-Gue ’rin(BCG)vaccination,which is immunogenic but not toxic.Another way is to use antibiotics such as kanamycin,streptomycin,rifampicin,cyloserine and so on.However,drug resistance is observed in all these antibiotics.The genome sequence of the M.tuberculosis H37Rv is known.But the function of many germ proteins are still unclear.The Rvlc protein,which belongs to the prophage-like elements φRv1,was discovered in the H37Rv bacteria.No other protein members in the same family has been discovered yet.Therefore studies of the structure and function of this protein does not be reported.Also a kinase receptor was shown to interact with Rv1c.In this study,we constructed expression vector of Rvlc gene,truncated Rv1c1-84 gene and the kinase receptor gene by molecular biological methods.The proteins were expressed in Escherichia coli,and purified by affinity chromatography,ion exchange and gel filtration chromatography.The interaction of the kinase receptor and Rv1c protein was confirmed by Pull-down and isothermal titration calorimetry(ITC).The result showed that both the Rv1c protein and the truncated Rv1c1-84 protein were able to interact with the the kinase receptor with Kd of 30μM and 49μM respectively.We obtained Rv1c1-84 protein crystals.And obtained 1.24 A structure of the Rv1c1-84 protein finally.The complex structure of the kinase receptor and Rvlc was predicted and the interaction region was estimated.The study showed that Rv1c protein could interact with the kinase receptor directly.We solved the crystal structure of the Rvlc1-84 protein and studied the molecular mechanism of the interaction through the predicted model of the protein complex.It could be very helpful for treatment of tuberculosis in the furture.