Cryo-EM structure and protease activity of the type III-E CRISPR-Cas effector.
Nat Microbiol
; 8(3): 522-532, 2023 03.
Article
en En
| MEDLINE
| ID: mdl-36702942
ABSTRACT
The recently discovered type III-E CRISPR-Cas effector Cas7-11 shows promise when used as an RNA manipulation tool, but its structure and the mechanisms underlying its function remain unclear. Here we present four cryo-EM structures of Desulfonema ishimotonii Cas7-11-crRNA complex in pre-target and target RNA-bound states, and the cryo-EM structure of DiCas7-11-crRNA bound to its accessory protein DiCsx29. These data reveal structural elements for pre-crRNA processing, target RNA cleavage and regulation. Moreover, a 3' seed region of crRNA is involved in regulating RNA cleavage activity of DiCas7-11-crRNA-Csx29. Our analysis also shows that both the minimal mismatch of 4 nt to the 5' handle of crRNA and the minimal matching of the first 12 nt of the spacer by the target RNA are essential for triggering the protease activity of DiCas7-11-crRNA-Csx29 towards DiCsx30. Taken together, we propose that target RNA recognition and cleavage regulate and fine-tune the protease activity of DiCas7-11-crRNA-Csx29, thus preventing auto-immune responses.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
ARN
/
Sistemas CRISPR-Cas
Idioma:
En
Revista:
Nat Microbiol
Año:
2023
Tipo del documento:
Article
País de afiliación:
China