This entry represents the C-terminal RNase toxin domain found in bacterial polymorphic toxin systems. The toxin possesses an all alpha-helical fold and conserved aspartate and glutamate residues, and K[DE] and [DN]HxxE motifs. In bacterial polymorphic toxin systems, the toxin is exported by the type 2, type 5 or type 7 secretion system [1]. This C-terminal domain cleaves within tRNA anticodon loops, tRNase activity that is stimulated by CysK which stabilises this domain and allows its binding to the tRNA substrate [2,3].

1: Polymorphic toxin systems: comprehensive characterization of trafficking modes, processing, mechanisms of action, immunity and ecology using comparative genomics. Zhang D, de Souza RF, Anantharaman V, Iyer LM, Aravind L; Biol Direct. 2012;7:18. PMID:22731697

2: Identification of a target cell permissive factor required for contact-dependent\tgrowth inhibition (CDI). Diner EJ, Beck CM, Webb JS, Low DA, Hayes CS; Genes Dev. 2012;26:515-525. PMID:22333533

3: Contact-dependent growth inhibition toxins exploit multiple independent cell-entry pathways. Willett JL, Gucinski GC, Fatherree JP, Low DA, Hayes CS; Proc Natl Acad Sci U S A. 2015;112:11341-11346. PMID:26305955