| Primary Identifier | IPR044153 | Type | Domain |
| Short Name | PIN_Pae0151-like |
| description | This PIN domain can be found in the Pyrobaculum aerophilum proteins, Pae0151 (also known as VapC3) and Pae2754 (also known as VapC9), and their homologues []. They are similar to the PIN domains of the Mycobacterium tuberculosis VapC and Neisseria gonorrhoeae FitB toxins of the prokaryotic toxin/antitoxin operons, VapBC and FitAB, respectively, which are believed to be involved in growth inhibition by regulating translation. These toxins are nearly always co-expressed with an antitoxin, a cognate protein inhibitor, forming an inert protein complex. Disassociation of the protein complex activates the ribonuclease activity of the toxin by an, as yet undefined mechanism [, ].PIN domains are small protein domains identified by the presence of three strictly conserved acidic residues. Apart from these three residues, there is poor sequence conservation []. PIN domains are found in eukaryotes, eubacteria and archaea. In eukaryotes they are ribonucleases involved in nonsense mediated mRNA decay []and in processing of 18S ribosomal RNA []. In prokaryotes, they are the toxic components of toxin-antitoxin (TA) systems, their toxicity arising by virtue of their ribonuclease activity. The PIN domain TA systems are now called VapBC TAs(virulence associated proteins), where VapB is the inhibitor and VapC, the PIN-domain ribonuclease toxin []. |
