SNAP output for PDB entry 2xd0 [SNAP web server]

PDB-id

2xd0; SNAP-derived features in text and JSON formats; DNAproDB

Class

toxin-RNA

Method

X-ray (3.0 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 GP (2011): "A processed noncoding RNA regulates an altruistic bacterial antiviral system." Nat. Struct. Mol. Biol., 18, 185-190. 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.