7ZJW

Rabbit 80S ribosome as it decodes the Sec-UGA codon

This is a non-PDB format compatible entry.

Summary for 7ZJW

• Entry DOI: 10.2210/pdb7zjw/pdb
• EMDB information: 14751
• Descriptor: eEFSec, 60S ribosomal protein L3, 60S ribosomal protein L4, ... (93 entities in total)
• Functional Keywords: selenocysteine, recoding, 80s, ribosome
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 86
• Total formula weight: 4626611.51

Authors

Hilal, T.,Simonovic, M.,Spahn, C.M.T. (deposition date: 2022-04-12, release date: 2022-10-19, Last modification date: 2024-04-24)

Primary citation

Hilal, T.,Killam, B.Y.,Grozdanovic, M.,Dobosz-Bartoszek, M.,Loerke, J.,Burger, J.,Mielke, T.,Copeland, P.R.,Simonovic, M.,Spahn, C.M.T.
Structure of the mammalian ribosome as it decodes the selenocysteine UGA codon.
Science, 376:1338-1343, 2022

PubMed Abstract: The elongation of eukaryotic selenoproteins relies on a poorly understood process of interpreting in-frame UGA stop codons as selenocysteine (Sec). We used cryo-electron microscopy to visualize Sec UGA recoding in mammals. A complex between the noncoding Sec-insertion sequence (SECIS), SECIS-binding protein 2 (SBP2), and 40 ribosomal subunit enables Sec-specific elongation factor eEFSec to deliver Sec. eEFSec and SBP2 do not interact directly but rather deploy their carboxyl-terminal domains to engage with the opposite ends of the SECIS. By using its Lys-rich and carboxyl-terminal segments, the ribosomal protein eS31 simultaneously interacts with Sec-specific transfer RNA (tRNA) and SBP2, which further stabilizes the assembly. eEFSec is indiscriminate toward l-serine and facilitates its misincorporation at Sec UGA codons. Our results support a fundamentally distinct mechanism of Sec UGA recoding in eukaryotes from that in bacteria.

PubMed: 35709277
DOI: 10.1126/science.abg3875

Experimental method

ELECTRON MICROSCOPY (2.8 Å)