Structural basis for the assembly of the type V CRISPR-associated transposon complex.
Cell
; 185(26): 4999-5010.e17, 2022 12 22.
Article
em En
| MEDLINE
| ID: mdl-36435179
ABSTRACT
CRISPR-Cas systems have been co-opted by Tn7-like transposable elements to direct RNA-guided transposition. Type V-K CRISPR-associated transposons rely on the concerted activities of the pseudonuclease Cas12k, the AAA+ ATPase TnsC, the Zn-finger protein TniQ, and the transposase TnsB. Here we present a cryo-electron microscopic structure of a target DNA-bound Cas12k-transposon recruitment complex comprised of RNA-guided Cas12k, TniQ, a polymeric TnsC filament and, unexpectedly, the ribosomal protein S15. Complex assembly, mediated by a network of interactions involving the guide RNA, TniQ, and S15, results in R-loop completion. TniQ contacts two TnsC protomers at the Cas12k-proximal filament end, likely nucleating its polymerization. Transposition activity assays corroborate our structural findings, implying that S15 is a bona fide component of the type V crRNA-guided transposon machinery. Altogether, our work uncovers key mechanistic aspects underpinning RNA-mediated assembly of CRISPR-associated transposons to guide their development as programmable tools for site-specific insertion of large DNA payloads.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Elementos de DNA Transponíveis
/
Proteínas Associadas a CRISPR
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article