Translation initiation at the CUU codon is mediated by the internal ribosome entry site of an insect picorna-like virus in vitro.

ABSTRACT: AUG-unrelated translation initiation was found in an insect picorna-like virus, Plautia stali intestine virus (PSIV). The positive-strand RNA genome of the virus contains two nonoverlapping open reading frames (ORFs). The capsid protein gene is located in the 3'-proximal ORF and lacks an AUG initiation codon. We examined the translation mechanism and the initiation codon of the capsid protein gene by using various dicistronic and monocistronic RNAs in vitro. The capsid protein gene was translated cap independently in the presence of the upstream cistron, indicating that the gene is translated by internal ribosome entry. Deletion analysis showed that the internal ribosome entry site (IRES) consisted of approximately 250 bases and that its 3' boundary extended slightly into the capsid-coding

SUBMITTER: Sasaki J 

PROVIDER: S-EPMC103943 | biostudies-literature | 1999 Feb

REPOSITORIES: biostudies-literature