Target motifs affecting natural immunity by a constitutive CRISPR-Cas system in Escherichia coli.

ABSTRACT: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR associated (cas) genes conform the CRISPR-Cas systems of various bacteria and archaea and produce degradation of invading nucleic acids containing sequences (protospacers) that are complementary to repeat intervening spacers. It has been demonstrated that the base sequence identity of a protospacer with the cognate spacer and the presence of a protospacer adjacent motif (PAM) influence CRISPR-mediated interference efficiency. By using an original transformation assay with plasmids targeted by a resident spacer here we show that natural CRISPR-mediated immunity against invading DNA occurs in wild type Escherichia coli. Unexpectedly, the strongest activity is observed with protospacer adjoining nucleotides (interfe

SUBMITTER: Almendros C 

PROVIDER: S-EPMC3506596 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature