Project description:Mycobacterium tuberculosis (MTB) is a species of pathogenic bacteria and the causative agent of tuberculosis. The type strain H37Rv has been sequenced in 1998, while many previous studies found its predicted genes exhibit frequent errors, particularly in start codons. Here, we applied a TMPP [(N-Succinimidyloxycarbonylmethyl) tris (2,4,6-trimethoxyphenyl) phosphonium bromide] labeling combined with StageTip separating strategy to characterize the N-terminal peptides. We identified 2,598 annotated proteins, which 1,078 proteins were labeled by TMPP.
Project description:Diverse chemical modifications fine-tune the function and metabolism of tRNA. Although tRNA modification is universal in all kingdoms of life, profiles of modifications, their functions, and physiological roles have not been elucidated in most organisms including the human pathogen, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis. To identify physiologically important modifications, we surveyed the tRNA of Mtb, using tRNA sequencing (tRNA-seq). Reverse transcription-derived error signatures in tRNA-seq predicted the sites and presence of 9 modifications. Several chemical treatments prior to tRNA-seq expanded the number of predictable modifications. Deletion of Mtb genes encoding two modifying enzymes, TruB and MnmA, eliminated their respective tRNA modifications, validating the presence of modified sites in tRNA species.
Project description:ROS can damage cellular components and is a key player in many cellular signaling. Tuberculosis remains a major global public health concern largely due to the ability of its causative agent-Mycobacterium tuberculosis (Mtb) to subvert ROS toxicity. DNA methylation deficiency was previously shown to attenuate the Mtb virulence. But the role of DNA methyltransferase in Mycobacteria survival and the link with ROS are unknown. Mycobacterial protein Rv3204 is a DNA methyltransferase specific for N4-methylcytosine instead of N6-methyladenine (m6A) or 5-methylocytosine (m5C). The survival rate of m4C methyltransferase deletion mutants was lowered, accompanied by higher accumulation of ROS and failure of upregulating the transcription of gene engaged in ROS clearance upon rifampin(Rif) exposure.
Project description:Mycobacterium tuberculosis, the causative agent of tuberculosis accounts for 1.5 million annual deaths worldwide. The two well-characterized strains of the parental H37 strain namely, H37Ra and H37Rv show different pathogenic phenotypes. In order to identify factors that are responsible for virulence, we compared the proteome and the phosphoproteome profiles of virulent (H37Rv) and virulence attenuated (H37Ra) strains of M. tuberculosis. Quantitative proteomic analysis resulted in the identification and quantitation of 2,709 proteins and 505 phosphosites. Comparative analysis revealed over 5-fold overexpression of several proteins associated with virulence. Our data indicates that there are definable molecular differences between H37Rv and H37Ra strains at both the proteome and phosphoproteome levels which may explain the virulence and phenotypic differences.
Project description:We analyzed the genes expressed, or the transcriptome, of bacilli (Mycobacterium tuberculosis) growing in fatty acids as sole carbon source. Using new technologies to massively sequence of RNA molecules we identified a group of genes that provides novel insight regarding the metabolic pathways and transcriptional regulation of latent M. Tuberculosis.
