Dual modes of CRISPR-associated transposon homing.
Cell
; 184(9): 2441-2453.e18, 2021 04 29.
Article
em En
| MEDLINE
| ID: mdl-33770501
Tn7-like transposons have co-opted CRISPR systems, including class 1 type I-F, I-B, and class 2 type V-K. Intriguingly, although these CRISPR-associated transposases (CASTs) undergo robust CRISPR RNA (crRNA)-guided transposition, they are almost never found in sites targeted by the crRNAs encoded by the cognate CRISPR array. To understand this paradox, we investigated CAST V-K and I-B systems and found two distinct modes of transposition: (1) crRNA-guided transposition and (2) CRISPR array-independent homing. We show distinct CAST systems utilize different molecular mechanisms to target their homing site. Type V-K CAST systems use a short, delocalized crRNA for RNA-guided homing, whereas type I-B CAST systems, which contain two distinct target selector proteins, use TniQ for RNA-guided DNA transposition and TnsD for homing to an attachment site. These observations illuminate a key step in the life cycle of CAST systems and highlight the diversity of molecular mechanisms mediating transposon homing.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Bactérias
/
Proteínas de Bactérias
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DNA Bacteriano
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Elementos de DNA Transponíveis
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RNA Guia de Cinetoplastídeos
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Transposases
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Proteínas Associadas a CRISPR
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article