4CXH: Regulation Of The Mammalian Elongation Cycle By 40s Subunit Rolling: A Eukaryotic-specific Ribosome Rearrangement

Citation:
Abstract
The extent to which bacterial ribosomes and the significantly larger eukaryotic ribosomes share the same mechanisms of ribosomal elongation is unknown. Here, we present subnanometer resolution cryoelectron microscopy maps of the mammalian 80S ribosome in the posttranslocational state and in complex with the eukaryotic eEF1AVal-tRNAGMPPNP ternary complex, revealing significant differences in the elongation mechanism between bacteria and mammals. Surprisingly, and in contrast to bacterial ribosomes, a rotation of the small subunit around its long axis and orthogonal to the well-known intersubunit rotation distinguishes the posttranslocational state from the classical pretranslocational state ribosome. We term this motion "subunit rolling." Correspondingly, a mammalian decoding complex visualized in substates before and after codon recognition reveals structural distinctions from the bacterial system. These findings suggest how codon recognition leads to GTPase activation in the mammalian system and demonstrate that in mammalia subunit rolling occurs during tRNA selection.
PDB ID: 4CXHDownload
MMDB ID: 121462
PDB Deposition Date: 2014/4/7
Updated in MMDB: 2017/09
Experimental Method:
electron microscopy
Resolution: 8.9  Å
Source Organism:
Oryctolagus cuniculus
Similar Structures:
Biological Unit for 4CXH: nonameric; determined by software (PQS)
Molecular Components in 4CXH
Label Count Molecule
Proteins (2 molecules)
1
Elongation Factor 1A
Molecule annotation
1
40S Ribosomal Protein Us12(Gene symbol: RPS23)
Molecule annotation
Nucleotides(7 molecules)
1
18S rRNA - H44
Molecule annotation
1
28S rRNA - H89
Molecule annotation
1
Transfer RNA
Molecule annotation
1
18S rRNA - H5-h14
Molecule annotation
1
18S rRNA - H8
Molecule annotation
1
28S rRNA - H95
Molecule annotation
1
Messenger RNA
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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