Bioinformatics Analysis of Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR) in the Genomes of Bacillus cereus Group

Abstract

CRISPR is a novel type of microbial defense system,which is unique in that it is invader-specific,adaptive and heritable.It is a recent breakthrough in understanding host-virus interactions.Bioinformatics methods including BLAST,multiple sequence alignment,and RNA structure prediction was used to analyze the CRISPR structures of 24 Bacillus cereus group genomes.CRISPR existed in 42% strains.Two types of RNA secondary structures derived from the repeat sequences were predicted,and demonstrated that stem-loop secondary structure might function in mediating the interaction between foreign genetic elements and CAS-encoded proteins.The sequence homologous among 31% spacer,phage,plasmid and the genomes of Bacillus cereus group further verified that spacer was likely to come from the exogenous mobile genetic factor.As most of the Bacillus cereus group strains contain multiple plasmids and prophages,the CRISPR research in Bacillus cereus group by this study would be help to reveal relationship between host strains with plasmid or host strains with phage.