Cas9 (CRISPR associated protein 9, formerly called Cas5, Csn1, or Csx12) is a 160 kilodalton protein which plays a vital role in the immunological defense of certain bacteria against DNA viruses and plasmids, and is heavily utilized in genetic engineering applications. Its main function is to cut DNA and thereby alter a cell's genome.

CRISPR/Cas9 is a gene-editing technology which involves two essential components: a guide RNA to match a desired target gene, and Cas9 (CRISPR-associated protein 9)—an endonuclease which causes a double-stranded DNA break, allowing modifications to the genome (see figure 1).

Feb 27, 2014 · The CRISPR-associated endonuclease Cas9 can be targeted to specific genomic loci by single guide RNAs (sgRNAs). Here, we report the crystal structure of Streptococcus pyogenes Cas9 in complex with sgRNA and its target DNA at 2.5 Å resolution.

Guide RNA (gRNA) and CRISPR-associated (Cas-9) proteins are the two essential components in CRISPR/Cas-9 system. The mechanism of CRISPR/Cas-9 genome editing contains three steps, recognition, cleavage, and repair.

May 29, 2024 · In this study, we determine the crRNA- and tracrRNA-directed trans -cleavage activity of Cas9 by testing a range of sequence- and structure-specific nucleic acid substrates, thereby developing...

Aug 24, 2022 · Cas9 enzymes rely on a dual guide RNA structure consisting of a CRISPR RNA (crRNA) guide and a trans-activating CRISPR RNA (tracrRNA) coactivator to cleave complementary DNA targets.

Jan 5, 2018 · RNA-guided RNA cleavage is programmable and site-specific, and we find that this activity can be exploited to reduce infection by single-stranded RNA phage in vivo. We also demonstrate that Cas9 can direct PAM-independent repression of gene expression in bacteria.

CRISPR-Cas9 is a type of immune system discovered in bacteria. Scientists have adapted its components into a biotechnology tool for editing DNA. Made up of a DNA-cutting enzyme (Cas9) and a programmable RNA molecule (guide RNA), CRISPR-Cas9 can be used to precisely target nearly any gene.

Jan 3, 2013 · Here, we engineer the type II bacterial CRISPR system to function with custom guide RNA (gRNA) in human cells. For the endogenous AAVS1 locus, we obtained targeting rates of 10 to 25% in 293T cells, 13 to 8% in K562 cells, and 2 to 4% in induced pluripotent stem cells.

Jan 5, 2018 · RNA-guided RNA cleavage is programmable and site-specific, and we find that this activity can be exploited to reduce infection by single-stranded RNA phage in vivo. We also demonstrate that Cas9 can direct PAM-independent repression of gene expression in bacteria.