Abstract
In bacteria and archaea, RNA-Seq deep sequencing methodology allows for the detection of abundance and processing sites of the small RNAs that comprise a CRISPR (clustered regularly interspaced short palindromic repeats) RNome. Comparative analyses of these CRISPR RNome sets highlight conserved patterns that include the gradual decline of CRISPR RNA abundance from the leader-proximal to the leader-distal end. In the present review, we discuss exceptions to these patterns that indicate the extensive impact of individual spacer sequences on CRISPR array transcription and RNA maturation. Spacer sequences can contain promoter and terminator elements and can promote the formation of CRISPR RNA–anti-CRISPR RNA duplexes. In addition, potential RNA duplex formation with host tRNA was observed. These factors can influence the functionality of CRISPR–Cas (CRISPR-associated) systems and need to be considered in the design of synthetic CRISPR arrays.
- antisense RNA
- clustered regularly interspaced short palindromic repeats (CRISPR)
- RNA processing
- RNA-Seq
Footnotes
CRISPR Evolution, Mechanisms and Infection: A Biochemical Society Focused Meeting held at the University of St Andrews, U.K., 17–19 June 2013. Organized and Edited by Emmanuelle Charpentier (Laboratory for Molecular Infection Medicine Sweden, Sweden), John van der Oost (Wageningen University, The Netherlands) and Malcolm White (University of St Andrews, U.K.).
Abbreviations: Cas, CRISPR-associated; CRISPR, clustered regularly interspaced short palindromic repeats; crRNA, CRISPR RNA; pre-crRNA, precursor CRISPR RNA
- © The Authors Journal compilation © 2013 Biochemical Society