A Functional Mini-Integrase in a Two-Protein-type V-C CRISPR System.
Mol Cell
; 73(4): 727-737.e3, 2019 02 21.
Article
en 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.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
ADN Bacteriano
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Integrasas
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Proteínas de Escherichia coli
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Endodesoxirribonucleasas
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Endonucleasas
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Escherichia coli
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Proteínas Asociadas a CRISPR
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Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas
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Sistemas CRISPR-Cas
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Edición Génica
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
2019
Tipo del documento:
Article