Structural Basis for the Rescue of Stalled Ribosomes: Structure of YaeJ Bound to the Ribosome

• DOI: 10.1126/science.1217443
• Publication Date: 2012-03-15T19:09:29Z
• Authors: Matthieu G. Gagnon; Sai V. Seetharaman; David Bulkley; Thomas A. Steitz
• Keywords: Thermus thermophilus; Eukaryotic Ribosome; Ribosome profiling

In bacteria, the hybrid transfer-messenger RNA (tmRNA) rescues ribosomes stalled on defective messenger RNAs (mRNAs). However, certain gram-negative bacteria have evolved proteins that are capable of rescuing in a tmRNA-independent manner. Here, we report 3.2 angstrom-resolution crystal structure rescue factor YaeJ bound to Thermus thermophilus 70S ribosome complex with initiator tRNA(i)(fMet) and short mRNA. The reveals C-terminal tail functions as sensor discriminate between actively translating by binding mRNA entry channel downstream A site head shoulder 30S subunit. This allows N-terminal globular domain sample different conformations, so its conserved GGQ motif is optimally positioned catalyze hydrolysis peptidyl-tRNA. gives insights into mechanism function provides basis for understanding how it ribosomes.