Proteolytic processing of mesonivirus replicase polyproteins by the viral 3C-like protease.
J Gen Virol
; 97(6): 1439-1445, 2016 06.
Article
em En
| MEDLINE
| ID: mdl-26977900
ABSTRACT
Mesoniviridae are a family of insect RNA viruses that diverged profoundly from other families of the Nidovirales. Mesonivirus replicative proteins are produced from large polyprotein (pp) precursors (pp1a and pp1ab) through proteolytic cleavage by the viral 3C-like protease (3CLpro) and, possibly, other proteases. Using recombinant forms of the Cavally virus 3CLpro and pp1a/pp1ab-derived substrates, we characterized 3CLpro cleavage sites in mesonivirus polyproteins. Our data lead us to suggest that 3CLpro cleaves the central and C-proximal regions of mesonivirus pp1a/pp1ab at 12 conserved sites. Compared to other nidovirus homologues, the mesonivirus 3CLpro features a distinct substrate specificity, with asparagine at P2 being a major specificity determinant. Furthermore, we provide evidence that expression of the ORF1b-encoded part of pp1ab involves a -1 ribosomal frameshift at a conserved GGAUUUU heptanucleotide sequence in the ORF1a/1b overlap region. Taken together, the study identifies critical steps in the expression and maturation of mesonivirus replicative proteins.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Virais
/
Cisteína Endopeptidases
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Processamento de Proteína Pós-Traducional
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Poliproteínas
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Nidovirales
Limite:
Animals
Idioma:
En
Revista:
J Gen Virol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Alemanha