RESUMEN
It has been shown that inactivation of the VapC toxin from the VapÐС toxin-antitoxin system prevents mycobacterial cells from transitioning to an ovoid state that meets the criteria of dormancy. The results indicate a potential target for medicines that prevent the development of latent tuberculosis infection and provide a basis to obtain bacterial cells for the testing of compounds that are active towards dormant forms of mycobacteria.
Asunto(s)
Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/antagonistas & inhibidores , Toxinas Bacterianas/metabolismo , Mycobacterium smegmatis/metabolismo , Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Tuberculosis Latente/genética , Tuberculosis Latente/metabolismo , Tuberculosis Latente/prevención & control , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Mycobacterium smegmatis/genéticaRESUMEN
The structure of various toxin-antitoxin (TA) families and the principles of their action are reviewed. TA loci are widely distributed in the genomes of eubacteria and archaea. Most TA systems are two-component and function in a similar way: a stable toxin alters vitally important cell functions and can be inactivated by a labile antitoxin.
Asunto(s)
Bacterias , Infecciones Bacterianas , Proteínas Bacterianas , Bacterias/genética , Bacterias/metabolismo , Infecciones Bacterianas/genética , Infecciones Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , HumanosRESUMEN
Four major families of bacterial histone-like proteins (HU, IHF, H-NS, FIS), united on the basis of structural similarity and performing specific structural and regulatory functions in the cell, are discussed. Histone-like proteins perform topological modification of the chromosome (twisting, bending, and folding) and directly regulate the functioning of promoters of individual operons. Histone-like proteins are critical for the regulation of cell metabolism, are involved in the response to environmental changes, and play a key role in the transition to and maintenance of the quiescent state of bacteria.
Asunto(s)
Bacterias/metabolismo , Proteínas Bacterianas/metabolismo , Cromatina/metabolismo , Histonas/metabolismo , Bacterias/genética , Proteínas Bacterianas/genética , Cromatina/genética , Cromosomas Bacterianos , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Histonas/clasificación , Histonas/genética , Operón , Regiones Promotoras GenéticasRESUMEN
The new model of obtaining of ovoid resting forms Mycobacterium smegmatis, which are morphologically different from vegetative (rod-like) cells, was developed. Ovoid forms were characterized by a drastically decreased level of metabolic activity, an increased stability to heat processing and antibiotics action, and also by prolonged (more than 2 months) storage time preserving colony-forming ability. Obtained resting forms of mycobacteria may be used in test-systems for checking efficiency of new medical agents against latent forms of tuberculosis and determination of role of these of those genes in entering rest state.