EIF4B, eIF4G and RNA regulate eIF4A activity in translation initiation by modulating the eIF4A conformational cycle.

ABSTRACT: Eukaryotic translation initiation factor eIF4A is a DEAD-box helicase that resolves secondary structure elements in the 5'-UTR of mRNAs during ribosome scanning. Its RNA-stimulated ATPase and ATP-dependent helicase activities are enhanced by other translation initiation factors, but the underlying mechanisms are unclear. DEAD-box proteins alternate between open and closed conformations during RNA unwinding. The transition to the closed conformation is linked to duplex destabilization. eIF4A is a special DEAD-box protein that can adopt three different conformations, an open state in the absence of ligands, a half-open state stabilized by the translation initiation factor eIF4G and a closed state in the presence of eIF4G and eIF4B. We show here that eIF4A alone does not measurably sample the

SUBMITTER: Harms U 

PROVIDER: S-EPMC4081068 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature