Molecular dissection of the prototype foamy virus (PFV) RNA 5'-UTR identifies essential elements of a ribosomal shunt.

ABSTRACT: The prototype foamy virus (PFV) is a nonpathogenic retrovirus that shows promise as a vector for gene transfer. The PFV (pre)genomic RNA starts with a long complex leader that can be folded into an elongated hairpin, suggesting an alternative strategy to cap-dependent linear scanning for translation initiation of the downstream GAG open reading frame (ORF). We found that the PFV leader carries several short ORFs (sORFs), with the three 5'-proximal sORFs located upstream of a structural element. Scanning-inhibitory hairpin insertion analysis suggested a ribosomal shunt mechanism, whereby ribosomes start scanning at the leader 5'-end and initiate at the downstream ORF via bypass of the central leader regions, which are inhibitory for scanning. We show that the efficiency of shunting depends

SUBMITTER: Schepetilnikov M 

PROVIDER: S-EPMC2761275 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature