SNAP output for PDB entry 2xdb [SNAP web server]

PDB-id

2xdb; SNAP-derived features in text and JSON formats; DNAproDB

Class

toxin-RNA

Method

X-ray (2.55 Å)

Summary

A processed non-coding RNA regulates a bacterial antiviral system

Reference

Blower TR, Pei XY, Short FL, Fineran PC, Humphreys DP, Luisi BF, Salmond GPC (2011): "A Processed Noncoding RNA Regulates an Altruistic Bacterial Antiviral System." Nat.Struct.Mol.Biol., 18, 185. doi: 10.1038/NSMB.1981.

Abstract

The ≥ 10³⁰ bacteriophages on Earth relentlessly drive adaptive coevolution, forcing the generation of protective mechanisms in their bacterial hosts. One such bacterial phage-resistance system, ToxIN, consists of a protein toxin (ToxN) that is inhibited in vivo by a specific RNA antitoxin (ToxI); however, the mechanisms for this toxicity and inhibition have not been defined. Here we present the crystal structure of the ToxN-ToxI complex from Pectobacterium atrosepticum, determined to 2.75-Å resolution. ToxI is a 36-nucleotide noncoding RNA pseudoknot, and three ToxI monomers bind to three ToxN monomers to generate a trimeric ToxN-ToxI complex. Assembly of this complex is mediated entirely through extensive RNA-protein interactions. Furthermore, a 2'-3' cyclic phosphate at the 3' end of ToxI, and catalytic residues, identify ToxN as an endoRNase that processes ToxI from a repetitive precursor but is regulated by its own catalytic product.