6UZ7

K.lactis 80S ribosome with p/PE tRNA and eIF5B

This is a non-PDB format compatible entry.

Summary for 6UZ7

• Entry DOI: 10.2210/pdb6uz7/pdb
• EMDB information: 20952
• Descriptor: 25S ribosomal RNA, KLLA0E00573p, KLLA0F04499p, ... (85 entities in total)
• Functional Keywords: translation, ribosome, initiation, eif5b
• Biological source: Kluyveromyces lactis; More
• Total number of polymer chains: 83
• Total formula weight: 4159148.69

Authors

Fernandez, I.S.,Huang, B.Y. (deposition date: 2019-11-14, release date: 2020-01-15, Last modification date: 2024-03-06)

Primary citation

Huang, B.Y.,Fernandez, I.S.
Long-range interdomain communications in eIF5B regulate GTP hydrolysis and translation initiation.
Proc.Natl.Acad.Sci.USA, 117:1429-1437, 2020

PubMed Abstract: Translation initiation controls protein synthesis by regulating the delivery of the first aminoacyl-tRNA to messenger RNAs (mRNAs). In eukaryotes, initiation is sophisticated, requiring dozens of protein factors and 2 GTP-regulated steps. The GTPase eIF5B gates progression to elongation during the second GTP-regulated step. Using electron cryomicroscopy (cryo-EM), we imaged an in vitro initiation reaction which is set up with purified yeast components and designed to stall with eIF5B and a nonhydrolyzable GTP analog. A high-resolution reconstruction of a "dead-end" intermediate at 3.6 Å allowed us to visualize eIF5B in its ribosome-bound conformation. We identified a stretch of residues in eIF5B, located close to the γ-phosphate of GTP and centered around the universally conserved tyrosine 837 ( numbering), that contacts the catalytic histidine of eIF5B (H480). Site-directed mutagenesis confirmed the essential role that these residues play in regulating ribosome binding, GTP hydrolysis, and translation initiation both in vitro and in vivo. Our results illustrate how eIF5B transmits the presence of a properly delivered initiator aminoacyl-tRNA at the P site to the distant GTPase center through interdomain communications and underscore the importance of the multidomain architecture in translation factors to sense and communicate ribosomal states.

PubMed: 31900355
DOI: 10.1073/pnas.1916436117

Experimental method

ELECTRON MICROSCOPY (3.6 Å)