Naturally occurring dicistronic cricket paralysis virus RNA is regulated by two internal ribosome entry sites.

ABSTRACT: Cricket paralysis virus is a member of a group of insect picorna-like viruses. Cloning and sequencing of the single plus-strand RNA genome revealed the presence of two nonoverlapping open reading frames, ORF1 and ORF2, that encode the nonstructural and structural proteins, respectively. We show that each ORF is preceded by one internal ribosome entry site (IRES). The intergenic IRES is located 6,024 nucleotides from the 5' end of the viral RNA and is more active than the IRES located at the 5' end of the RNA, providing a mechanistic explanation for the increased abundance of structural proteins relative to nonstructural proteins in infected cells. Mutational analysis of this intergenic-region IRES revealed that ORF2 begins with a noncognate CCU triplet. Complementarity of this CCU triplet

SUBMITTER: Wilson JE 

PROVIDER: S-EPMC85949 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature