2xd0

Publication Abstract from PubMed

The >/=10(30) 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-A 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.

A processed noncoding RNA regulates an altruistic bacterial antiviral system.,Blower TR, Pei XY, Short FL, Fineran PC, Humphreys DP, Luisi BF, Salmond GP Nat Struct Mol Biol. 2011 Feb;18(2):185-90. Epub 2011 Jan 16. PMID:21240270^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.