Direct functional interaction of initiation factor eIF4G with type 1 internal ribosomal entry sites.

ABSTRACT: Viral internal ribosomal entry sites (IRESs) mediate end-independent translation initiation. There are 4 major structurally-distinct IRES groups: type 1 (e.g., poliovirus) and type 2 (e.g., encephalomyocarditis virus), which are dissimilar except for a Yn-Xm-AUG motif at their 3' borders, type 3 (e.g., hepatitis C virus), and type 4 (dicistroviruses). Type 2-4 IRESs mediate initiation by distinct mechanisms that are nevertheless all based on specific noncanonical interactions with canonical components of the translation apparatus, such as eukaryotic initiation factor (eIF) 4G (type 2), 40S ribosomal subunits (types 3 and 4), and eIF3 (type 3). The mechanism of initiation on type 1 IRESs is unknown. We now report that domain V of type 1 IRESs, which is adjacent to the Yn-Xm-AUG motif, speci

SUBMITTER: de Breyne S 

PROVIDER: S-EPMC2695064 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature