RESUMO
Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a serious threat to global public health. Fluoroquinolones (FQs) are effective against M. tuberculosis; however, resistant strains have limited their efficacy. Mycobacterium fluoroquinolone resistance protein A (MfpA) confers intrinsic resistance to FQs; however, its regulatory mechanisms remain largely unknown. Using M. smegmatis as a model, we investigated whether MfpC is necessary for FQ susceptibility. MfpC mutants were sensitive to moxifloxacin, indicating that MfpC is involved in FQ susceptibility. By testing the mfpC inactivation phenotype in different mutants and using mycobacterial protein fragment complementation, we demonstrated that the function of MfpC depends on its interactions with MfpB. Guanine nucleotide exchange assays and site-directed mutagenesis confirmed that MfpC acts as a guanine nucleotide exchange factor to regulate MfpB. We propose that MfpB influences MfpA at the translational level. In summary, we reveal the role of MfpC in regulating the function of MfpA in FQ resistance.
Assuntos
Proteínas de Bactérias , Fluoroquinolonas , Mycobacterium smegmatis , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/metabolismo , Mycobacterium smegmatis/efeitos dos fármacos , Fluoroquinolonas/farmacologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Regulação Bacteriana da Expressão Gênica , MutaçãoRESUMO
CRISPR-Cas systems are the only RNA- guided adaptive immunity pathways that trigger the detection and destruction of invasive phages and plasmids in bacteria and archaea. Due to its prevalence and mystery, the Class 1 CRISPR-Cas system has lately been the subject of several studies. This review highlights the specificity of CRISPR-Cas system III-A in Mycobacterium tuberculosis, the tuberculosis-causing pathogen, for over twenty years. We discuss the difference between the several subtypes of Type III and their defence mechanisms. The anti-CRISPRs (Acrs) recently described, the critical role of Reverse transcriptase (RT) and housekeeping nuclease for type III CRISPR-Cas systems, and the use of this cutting-edge technology, its impact on the search for novel anti-tuberculosis drugs.