DNA capture by a CRISPR-Cas9-guided adenine base editor.
Science
; 369(6503): 566-571, 2020 07 31.
Article
em En
| MEDLINE
| ID: mdl-32732424
ABSTRACT
CRISPR-Cas-guided base editors convert Aâ¢T to Gâ¢C, or Câ¢G to Tâ¢A, in cellular DNA for precision genome editing. To understand the molecular basis for DNA adenosine deamination by adenine base editors (ABEs), we determined a 3.2-angstrom resolution cryo-electron microscopy structure of ABE8e in a substrate-bound state in which the deaminase domain engages DNA exposed within the CRISPR-Cas9 R-loop complex. Kinetic and structural data suggest that ABE8e catalyzes DNA deamination up to ~1100-fold faster than earlier ABEs because of mutations that stabilize DNA substrates in a constrained, transfer RNA-like conformation. Furthermore, ABE8e's accelerated DNA deamination suggests a previously unobserved transient DNA melting that may occur during double-stranded DNA surveillance by CRISPR-Cas9. These results explain ABE8e-mediated base-editing outcomes and inform the future design of base editors.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
DNA
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Adenina
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Adenosina Desaminase
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Proteínas de Escherichia coli
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Sistemas CRISPR-Cas
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Edição de Genes
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Proteína 9 Associada à CRISPR
Idioma:
En
Revista:
Science
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos