Characteristics and applications of different types of CRISPR-Cas tools

Adaptivna imunost kod bakterija i arheja ili pod akronimom poznat sustav CRISPR-Cas (engl. clustered regularly interspaced short palindromic repeats-CRISPR associated proteins) prenamijenjen je u trenutno najkorišteniji genetički alat. Njegova je posebnost u tome što specifično prepoznaje sekvence RNA ili DNA prema sekvenci molekule RNA koja ga vodi pa omogućava precizno djelovanje alata. U ovom su radu predstavljeni alati dizajnirani na temelju sustava CRISPR-Cas iz klase 2. Klasa 2 pogodna je za manipulaciju kod dizajna alata zbog toga što posjeduje jedan efektorski protein. Efektorski proteini unutar klase 2 su Cas9 i Cas12 koji prepoznaju dvolančanu DNA i Cas13 koji prepoznaje jednolančanu RNA. Svaki od efektorskih proteina posjeduje specifičan mehanizam djelovanja zbog kojeg je pogodniji za određen tip alata. Naravno, dizajn svakog genetičkog alata sa sobom nosi pregršt problema poput unosa u stanice i nespecifično djelovanje (off-target) koji su diskutirani u ovom radu.Bacterial and archaeal adaptive immunity or system more known as CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated proteins) was repurposed in currently the most used genetic tool. The system can specifically target an RNA or DNA sequence because it is guided by an RNA molecule which enables tool precision. This paper represents different tools based on class 2 CRISPR-Cas system. The class 2 is better suited as a tool because it has a single effector protein. Class 2 effector proteins are Cas9 and Cas12 which bind dsDNA and Cas13 which binds ssRNA. Each of these effector proteins has its unique mechanism of action which makes it more convenient for a specific type of a genetic tool. Moreover, designing a genetic tool brings a handful of problems such as delivery into cells and off-target activity both discussed in this paper