Mechanism of translation inhibition by type II GNAT toxin AtaT2.

Type II toxin-antitoxins systems are widespread in prokaryotic genomes. Typically, they comprise two proteins, a toxin, and an antitoxin, encoded by adjacent genes and forming a complex in which the enzymatic activity of the toxin is inhibited. Under stress conditions, the antitoxin is degraded liberating the active toxin.

Structural Basis of Leader Peptide Recognition in Lasso Peptide Biosynthesis Pathway.

Lasso peptides are a class of ribosomally synthesized and post-translationally modified peptides (RiPPs) with a unique 3D-interlocked structure, in which an N-terminal macrolactam ring is threaded by a linear C-terminal part. The unique structure of lasso peptides is introduced into ribosomally translated precursor peptides by lasso peptide synthetase encompassing proteins B and C or B1, B2, and C when the B enzyme is split into two distinct proteins. The B1 protein recognizes the leader sequence of the precursor peptide, and then the B2 protein cleaves it.

Escherichia coli ItaT is a type II toxin that inhibits translation by acetylating isoleucyl-tRNAIle.

Prokaryotic toxin-antitoxin (TA) modules are highly abundant and are involved in stress response and drug tolerance. The most common type II TA modules consist of two interacting proteins. The type II toxins are diverse enzymes targeting various essential intracellular targets.