Sliding of a 43S ribosomal complex from the recognized AUG codon triggered by a delay in eIF2-bound GTP hydrolysis.

ABSTRACT: During eukaryotic translation initiation, 43S ribosomal complex scans mRNA leader unless an AUG codon in an appropriate context is found. Establishing the stable codon-anticodon base-pairing traps the ribosome on the initiator codon and triggers structural rearrangements, which lead to Pi release from the eIF2-bound GTP. It is generally accepted that AUG recognition by the scanning 43S complex sets the final point in the process of start codon selection, while latter stages do not contribute to this process. Here we use translation reconstitution approach and kinetic toe-printing assay to show that after the 48S complex is formed on an AUG codon, in case GTP hydrolysis is impaired, the ribosomal subunit is capable to resume scanning and slides downstream to the next AUG. In contrast to lea

SUBMITTER: Terenin IM 

PROVIDER: S-EPMC4770231 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature