Resurrection of a Viral Internal Ribosome Entry Site from a 700 Year Old Ancient Northwest Territories Cripavirus.
Viruses
; 13(3)2021 03 17.
Article
em En
| MEDLINE
| ID: mdl-33802878
ABSTRACT
The dicistrovirus intergenic region internal ribosome entry site (IGR IRES) uses an unprecedented, streamlined mechanism whereby the IRES adopts a triple-pseudoknot (PK) structure to directly bind to the conserved core of the ribosome and drive translation from a non-AUG codon. The origin of this IRES mechanism is not known. Previously, a partial fragment of a divergent dicistrovirus RNA genome, named ancient Northwest territories cripavirus (aNCV), was extracted from 700-year-old caribou feces trapped in a subarctic ice patch. The aNCV IGR sequence adopts a secondary structure similar to contemporary IGR IRES structures, however, there are subtle differences including 105 nucleotides upstream of the IRES of unknown function. Using filter binding assays, we showed that the aNCV IRES could bind to purified ribosomes, and toeprinting analysis pinpointed the start site at a GCU alanine codon adjacent to PKI. Using a bicistronic reporter RNA, the aNCV IGR can direct translation in vitro in a PKI-dependent manner. Lastly, a chimeric infectious clone swapping in the aNCV IRES supported translation and virus infection. The characterization and resurrection of a functional IGR IRES from a divergent 700-year-old virus provides a historical framework for the importance of this viral translational mechanism.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Rena
/
Dicistroviridae
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Sítios Internos de Entrada Ribossomal
Limite:
Animals
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Viruses
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Canadá