Q8IYD1: Eukaryotic peptide chain release factor GTP-binding subunit ERF3B (GSPT2)

Eukaryotic peptide chain release factor GTP-binding subunit ERF3B (GSPT2) is a 628-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q8IYD1.

Gene
GSPT2
Organism
Homo sapiens
Length
628 residues
Mean pLDDT
74.2
Model
AF-Q8IYD1-F1 v6
Model created
1 Aug 2025
PDB structures
1

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Model confidence (pLDDT)

The mean pLDDT of this model is 74.2 (confident overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.

pLDDT bandMeaningShare of residues
Above 90Very high: backbone and side chains are usually accurate48%
70 to 90Confident: backbone generally right21%
50 to 70Low: treat with caution4%
Below 50Very low: often disordered regions28%

What pLDDT means and how to read it

Function

GTPase component of the eRF1-eRF3-GTP ternary complex, a ternary complex that mediates translation termination in response to the termination codons UAA, UAG and UGA (PubMed:11524954, PubMed:15987998, PubMed:17562865). GSPT2/ERF3B mediates ETF1/ERF1 delivery to stop codons: The eRF1-eRF3-GTP complex binds to a stop codon in the ribosomal A-site (PubMed:15987998). GTP hydrolysis by GSPT2/ERF3B induces a conformational change that leads to its dissociation, permitting ETF1/ERF1 to accommodate fully in the A-site (PubMed:15987998). Component of the transient SURF complex which recruits UPF1 to stalled ribosomes in the context of nonsense-mediated decay (NMD) of mRNAs containing premature stop…

Subunit structure

Component of the eRF1-eRF3-GTP ternary complex, composed of ETF1/ERF1 and ERF3 (GSPT1/ERF3A or GSPT2/ERF3B) and GTP (PubMed:15987998). Component of the transient SURF (SMG1-UPF1-eRF1-eRF3) complex (PubMed:19417104). Interacts with UPF1 and PABPC1 (PubMed:18447585)

Subcellular location

Cytoplasm

Experimental structures in the PDB

Compare the prediction with experimentally determined structures of the same protein:

PDB IDMethodResolutionChains and residues
3KUJX-ray1.4 ÅB=59-73

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