Original story from Helmholtz Centre for Infection Research (Braunschweig, Germany). Scientists have discovered a new CRISPR mechanism with precise activity, expanding the potential applications of the existing CRISPR toolbox. The CRISPR ‘gene scissors’ have become an important basis for genome-editing technologies in many fields, ranging from biology and medicine to agriculture and industry. A team from the Helmholtz Institute for RNA-based Infection Research (HIRI; Würzburg, Germany) has now demonstrated that these CRISPR-Cas systems are even more versatile than previously thought. In cooperation with the Helmholtz Centre for Infection Research (HZI; Braunschweig, Germany) and Utah State University (USU; UT, USA), the scientists have discovered a novel CRISPR defense mechanism: Unlike known nucleases, Cas12a3 specifically destroys transfer ribonucleic acids (tRNA) that are vital for protein production to shut down infected cells. The team published its findings today in the journal Nature. Bacteria contain a wide variety of mechanisms to fend off invaders like viruses. One of these strategies involves cleaving tRNA, which are present in all cells and play a fundamental role in the translation of messenger RNA into essential proteins. Their inactivation limits protein production, causing the infected cell to go dormant. As a result, the attacker cannot continue to replicate and spread within the bacterial population. One common bacterial defense that has so far not been associated with tRNA cleavage are CRISPR-Cas systems. CRISPR uses RNA-guided proteins, known as Cas nucleases (from CRISPR-associated), to recognize invaders based on their genetic material and deactivate them. Once they identify a pathogen, the…
