Initiation on the divergent Type I cadicivirus IRES: factor requirements and interactions with the translation apparatus.

ABSTRACT: Cadicivirus (CDV) is unique amongst picornaviruses in having a dicistronic genome with internal ribosomal entry sites (IRESs) preceding both open reading frames. Here, we investigated initiation on the 5'-terminal IRES. We report that the 982-nt long 5'UTR comprises 12 domains (d1-d12), five of which (d8-d12, nts 341-950) constitute a divergent Type I IRES. It comprises central elements (the apex of d10, d11 and the following polypyrimidine tract) that are homologous to corresponding elements in canonical Type 1 IRESs, and non-canonical flanking domains (d8, d9 and d12). In vitro reconstitution revealed that as with canonical Type I IRESs, 48S complex formation requires eukaryotic initiation factors (eIFs) 1, 1A, 2, 3, 4A, 4B and 4G, and the poly(C) binding protein 2 (PCBP2), and starts wi

SUBMITTER: Asnani M 

PROVIDER: S-EPMC4838371 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature