PMID: 20829488 , Related PDB ids: 2XLI, 2XLJ, 2XLK

Authors:

Haurwitz RE, Jinek M, Wiedenheft B, Zhou K, Doudna JA

Title:

Sequence- and structure-specific RNA processing by a CRISPR endonuclease.

Journal:

Science. 2010 Sep 10;329(5997):1355-8.

Abstract:

Many bacteria and archaea contain clustered regularly interspaced short palindromic repeats (CRISPRs) that confer resistance to invasive genetic elements. Central to this immune system is the production of CRISPR-derived RNAs (crRNAs) after transcription of the CRISPR locus. Here, we identify the endoribonuclease (Csy4) responsible for CRISPR transcript (pre-crRNA) processing in Pseudomonas aeruginosa. A 1.8 angstrom crystal structure of Csy4 bound to its cognate RNA reveals that Csy4 makes sequence-specific interactions in the major groove of the crRNA repeat stem-loop. Together with electrostatic contacts to the phosphate backbone, these enable Csy4 to bind selectively and cleave pre-crRNAs using phylogenetically conserved serine and histidine residues in the active site. The RNA recognition mechanism identified here explains sequence- and structure-specific processing by a large family of CRISPR-specific endoribonucleases.