Titre : |
The tuberculosis necrotizing toxin kills macrophages by hydrolyzing NAD |
Type de document : |
document électronique |
Auteurs : |
Jim Sun, Auteur ; Alex Siroy, Auteur ; Ravi K. Lokareddy, Auteur |
Editeur : |
Nature Publishing Group |
Année de publication : |
2015 |
Collection : |
Nature structural & molecular biology., ISSN 1545-9985 num. 22(9) |
Importance : |
p.672-678 |
Langues : |
Anglais moyen (ca.1100-1500) (enm) |
Catégories : |
[DIVERS] discipline médicale, paramédicale et scientifique:biochimie [TUBER] cause:bacille de Koch
|
Index. décimale : |
TU 5.3. Biologie moléculaire (résistance) / microbiologie |
Résumé : |
Mycobacterium tuberculosis (Mtb) induces necrosis of infected cells to evade immune responses. Recently, we found that Mtb utilizes the protein CpnT to kill human macrophages by secreting its C-terminal domain, named tuberculosis necrotizing toxin (TNT) that induces necrosis by an unknown mechanism. Here we show that TNT gains access to the cytosol of Mtb-infected macrophages, where it hydrolyzes the essential co-enzyme nicotinamide adenine dinucleotide (NAD+). Expression or injection of a non-catalytic TNT mutant showed no cytotoxicity in macrophages or zebrafish zygotes, respectively, demonstrating that the NAD+-glycohydrolase activity is required for TNT-induced cell death. To prevent self-poisoning, Mtb produces an immunity factor for TNT (IFT) that binds TNT and inhibits its activity. The crystal structure of the TNT-IFT complex revealed a novel NAD+-glycohydrolase fold of TNT, which constitutes the founding member of a toxin family wide-spread in pathogenic microorganisms. |
En ligne : |
https://doi.org/10.1038/nsmb.3064 |
Format de la ressource électronique : |
HTML, PDF |
Permalink : |
https://biblio.fares.be/opac_css/index.php?lvl=notice_display&id=9406 |