Expanding the CRISPR Toolbox: Targeting RNA with Cas13b

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• CRISPR-Cas systems provide adaptive immunity in prokaryotes.
• Type VI CRISPR-Cas systems are known for their RNA-guided RNA-targeting capabilities.

Purpose of the Study:

• To identify and characterize novel CRISPR-Cas components.
• To elucidate the RNA-targeting mechanism of Cas13b.

Main Methods:

• Bioinformatic analysis to identify Cas13b.
• In vitro biochemical assays to characterize enzyme activity.
• RNA-binding and cleavage assays.

Main Results:

• Cas13b was identified as a key enzyme in type VI-B CRISPR-Cas systems.
• Cas13b exhibits RNA-guided, RNA-targeting activity.
• The activity of Cas13b is modulated by co-factors Csx27 and Csx28.
• Cas13b demonstrates non-specific RNA cleavage as collateral damage.

Conclusions:

• Cas13b is a novel RNA-targeting enzyme within type VI-B CRISPR-Cas systems.
• Csx27 and Csx28 are regulators of Cas13b function.
• Understanding Cas13b's collateral activity is crucial for its biotechnological applications.