A Functional Mini-Integrase in a Two-Protein-type V-C CRISPR System.
Mol Cell
; 73(4): 727-737.e3, 2019 02 21.
Article
em En
| MEDLINE
| ID: mdl-30709710
ABSTRACT
CRISPR-Cas immunity requires integration of short, foreign DNA fragments into the host genome at the CRISPR locus, a site consisting of alternating repeat sequences and foreign-derived spacers. In most CRISPR systems, the proteins Cas1 and Cas2 form the integration complex and are both essential for DNA acquisition. Most type V-C and V-D systems lack the cas2 gene and have unusually short CRISPR repeats and spacers. Here, we show that a mini-integrase comprising the type V-C Cas1 protein alone catalyzes DNA integration with a preference for short (17- to 19-base-pair) DNA fragments. The mini-integrase has weak specificity for the CRISPR array. We present evidence that the Cas1 proteins form a tetramer for integration. Our findings support a model of a minimal integrase with an internal ruler mechanism that favors shorter repeats and spacers. This minimal integrase may represent the function of the ancestral Cas1 prior to Cas2 adoption.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Bacteriano
/
Integrases
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Proteínas de Escherichia coli
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Endodesoxirribonucleases
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Endonucleases
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Escherichia coli
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Proteínas Associadas a CRISPR
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Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas
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Sistemas CRISPR-Cas
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Edição de Genes
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos