CRISPR stand for: Clustered Regularly Interspaced Short Palindromic Repeat. The CRISPR is repeat spacer array contain a series of short direct repeats interspaced with short sequence which had been detected in the genome of many bacteria and archaea. The CRISPR method is based on the natural defense system used by bacteria to protect themselves from invading viruses. When the DNA of virus detected by bacterium, the CRISPR RNA as a guide RNA which contain a sequence, match to the invading virus DNA, the adoptive immunity occurs in three steps: first CRISPR acquisition, a short sequence of invading DNA ( ̴ 30 nucleotide) as a spacer sequence insert to the CRISPR locus. Second, CRISPR expression, which CRISPR are transcribed as a single large
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Near to all of them could be categorized to the most adopted, 3 main groups, (type I, type II and type III). These classes could be sub grouped to Different classes such as sub type IA, IIA, IB, IIIB and etc.
In all identified CRISPR system, Cas 1 and Cas 2 proteins are presented. They involved in spacer integration which occurs during the adoption or acquisition step and regarded as a “core Cas proteins”. In the other hand, other Cas proteins are different in different type of system. Due to these difference, some system work by target the DNA, while others target and cleave the RNA.
For example, in type I, the presence of Cas 3 gene, encode a large protein responsible for degrading target. The different sub groups of this type contain a variable number of Cas genes. Type II include HNH system and encode the Cas 9 protein which participate in acquisition, CrRNA processing and cleavage of target DNA. Type III contain Cas 10 …show more content…
They observed Cas1Cas2 complex contain a constant concentration of Cas 1 and 2 concentration of Cas 2 and a strong peak with the molecular weight distribution of ̴ 78 which was a sum of one Cas1 dimer and one Cas 2 dimer. Thus these observation support the calculated stoichiometry from ITC data. Also, retention time of the complex on a gel-filtration column was also consistent with the AUC
Near to all of them could be categorized to the most adopted, 3 main groups, (type I, type II and type III). These classes could be sub grouped to Different classes such as sub type IA, IIA, IB, IIIB and etc.
In all identified CRISPR system, Cas 1 and Cas 2 proteins are presented. They involved in spacer integration which occurs during the adoption or acquisition step and regarded as a “core Cas proteins”. In the other hand, other Cas proteins are different in different type of system. Due to these difference, some system work by target the DNA, while others target and cleave the RNA.
For example, in type I, the presence of Cas 3 gene, encode a large protein responsible for degrading target. The different sub groups of this type contain a variable number of Cas genes. Type II include HNH system and encode the Cas 9 protein which participate in acquisition, CrRNA processing and cleavage of target DNA. Type III contain Cas 10 …show more content…
They observed Cas1Cas2 complex contain a constant concentration of Cas 1 and 2 concentration of Cas 2 and a strong peak with the molecular weight distribution of ̴ 78 which was a sum of one Cas1 dimer and one Cas 2 dimer. Thus these observation support the calculated stoichiometry from ITC data. Also, retention time of the complex on a gel-filtration column was also consistent with the AUC