Detailed 3D structure of the Cas13d enzyme with guide RNA and unintended target RNA

Cryoelectron microscopy revealed RfxCas13d structures at 3.10 and 3.13 Å resolution.

• The ternary complex includes RfxCas13d, crRNA, and a short off-target single-stranded RNA.
• RfxCas13d exhibits conformational changes in the presence or absence of off-target RNA.
• Catalytic sites of RfxCas13d remain unchanged despite these conformational changes.
• The stabilization of the crRNA repeat region structure may be important for RNA binding.
• Findings provide a foundation for further development of RfxCas13d in transcriptome engineering.

Simplified