Abstract
Irreversible GTP hydrolysis by eIF2 is a critical step in translation initiation in eukaryotes because it is thought to commit the translational machinery to assembling the ribosomal complex at the selected point in the mRNA. Our quantitative analysis of the steps and interactions involved in activating GTP hydrolysis by eIF2 during translation initiation in vitro indicates that a structural rearrangement in the 43S preinitiation complex activates it to become fully competent to hydrolyze GTP. Contrary to the prevailing model, release of inorganic phosphate after GTP hydrolysis by eIF2, not hydrolysis itself, is controlled by recognition of the AUG codon. Release of Pi, which makes GTP hydrolysis irreversible, appears to be controlled by the AUG-dependent dissociation of eIF1 from the preinitiation complex.
Original language | English (US) |
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Pages (from-to) | 251-262 |
Number of pages | 12 |
Journal | Molecular cell |
Volume | 20 |
Issue number | 2 |
DOIs | |
State | Published - Oct 28 2005 |
Externally published | Yes |
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology