GNAT toxins evolve toward narrow tRNA target specificities.
Nucleic Acids Res
; 50(10): 5807-5817, 2022 06 10.
Article
em En
| MEDLINE
| ID: mdl-35609997
ABSTRACT
Type II toxin-antitoxin (TA) systems are two-gene modules widely distributed among prokaryotes. GNAT toxins associated with the DUF1778 antitoxins represent a large family of type II TAs. GNAT toxins inhibit cell growth by disrupting translation via acetylation of aminoacyl-tRNAs. In this work, we explored the evolutionary trajectory of GNAT toxins. Using LC/MS detection of acetylated aminoacyl-tRNAs combined with ribosome profiling, we systematically investigated the in vivo substrate specificity of an array of diverse GNAT toxins. Our functional data show that the majority of GNAT toxins are specific to Gly-tRNA isoacceptors. However, the phylogenetic analysis shows that the ancestor of GNAT toxins was likely a relaxed specificity enzyme capable of acetylating multiple elongator tRNAs. Together, our data provide a remarkable snapshot of the evolution of substrate specificity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Toxinas Bacterianas
/
Antitoxinas
/
Sistemas Toxina-Antitoxina
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2022
Tipo de documento:
Article