A cis-acting replication element in the sequence encoding the NS5B RNA-dependent RNA polymerase is required for hepatitis C virus RNA replication.
J Virol
; 78(3): 1352-66, 2004 Feb.
Article
en En
| MEDLINE
| ID: mdl-14722290
ABSTRACT
RNA structures play key roles in the replication of RNA viruses. Sequence alignment software, thermodynamic RNA folding programs, and classical comparative phylogenetic analysis were used to build models of six RNA elements in the coding region of the hepatitis C virus (HCV) RNA-dependent RNA polymerase, NS5B. The importance of five of these elements was evaluated by site-directed mutagenesis of a subgenomic HCV replicon. Mutations disrupting one of the predicted stem-loop structures, designated 5BSL3.2, blocked RNA replication, implicating it as an essential cis-acting replication element (CRE). 5BSL3.2 is about 50 bases in length and is part of a larger predicted cruciform structure (5BSL3). As confirmed by RNA structure probing, 5BSL3.2 consists of an 8-bp lower helix, a 6-bp upper helix, a 12-base terminal loop, and an 8-base internal loop. Mutational analysis and structure probing were used to explore the importance of these features. Primary sequences in the loops were shown to be important for HCV RNA replication, and the upper helix appears to serve as an essential scaffold that helps maintain the overall RNA structure. Unlike certain picornavirus CREs, whose function is position independent, 5BSL3.2 function appears to be context dependent. Understanding the role of 5BSL3.2 and determining how this new CRE functions in the context of previously identified elements at the 5' and 3' ends of the RNA genome should provide new insights into HCV RNA replication.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Replicación Viral
/
ARN Polimerasa Dependiente del ARN
/
ARN Viral
/
Elementos de Facilitación Genéticos
/
Proteínas no Estructurales Virales
/
Hepacivirus
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Virol
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos