Assuntos
Clonagem Molecular , Dados de Sequência Molecular , Hemoglobinas/genética , Hemoglobinas/metabolismo , Hemoglobinas/química , Homologia de Sequência de Aminoácidos , Ligantes , Modelos Moleculares , Mycobacterium leprae , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Sequência de Aminoácidos , Sequência de BasesRESUMO
Leprosy is an old, still dreaded infectious disease caused by the obligate intracellular bacterium Mycobacterium leprae. During the infectious process, M. leprae is faced with the host macrophagic environment, where the oxidative stress and NO release, combined with low pH, low pO2, and high pCO2, contribute to limit the growth of the bacilli. Comparative genomics has unraveled massive gene decay in M. leprae, linking the strictly parasitic lifestyle with the reductive genome evolution. Compared with Mycobacterium tuberculosis and Mycobacterium bovis, the leprosy bacillus has lost most of the genes involved in the detoxification of reactive oxygen and nitrogen species. The very low reactivity of the unique truncated hemoglobin retained by M. leprae could account for the susceptibility of this exceptionally slow-growing microbe to NO.