CRISPR/Cas9 searches for a protospacer adjacent motif by lateral diffusion.
EMBO J
; 38(4)2019 02 15.
Article
en En
| MEDLINE
| ID: mdl-30573670
ABSTRACT
The Streptococcus pyogenes CRISPR/Cas9 (SpCas9) nuclease has been widely applied in genetic engineering. Despite its importance in genome editing, aspects of the precise molecular mechanism of Cas9 activity remain ambiguous. In particular, because of the lack of a method with high spatio-temporal resolution, transient interactions between Cas9 and DNA could not be reliably investigated. It therefore remains controversial how Cas9 searches for protospacer adjacent motif (PAM) sequences. We have developed single-molecule Förster resonance energy transfer (smFRET) assays to monitor transient interactions of Cas9 and DNA in real time. Our study shows that Cas9 interacts with the PAM sequence weakly, yet probing neighboring sequences via facilitated diffusion. This dynamic mode of interactions leads to translocation of Cas9 to another PAM nearby and consequently an on-target sequence. We propose a model in which lateral diffusion competes with three-dimensional diffusion and thus is involved in PAM finding and consequently on-target binding. Our results imply that the neighboring sequences can be very important when choosing a target in genetic engineering applications.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Streptococcus pyogenes
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ADN
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Ingeniería Genética
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Motivos de Nucleótidos
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Sistemas CRISPR-Cas
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Edición Génica
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
EMBO J
Año:
2019
Tipo del documento:
Article
País de afiliación:
Países Bajos