Related Experiment Video

Updated: May 24, 2026

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
10:37

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs

Published on: May 10, 2018

Selectivity of stop codon recognition in translation termination is modulated by multiple conformations of GTS loop

Leo E Wong1, Yan Li, Shubhadra Pillay

  • 1School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.

Nucleic Acids Research
|March 3, 2012
PubMed

Insights

Structural insights into eukaryotic translation termination reveal how the eRF1 release factor recognizes stop codons. The GTS loop

Area of Science:

  • Molecular Biology
  • Structural Biology
  • Genetics

Background:

  • Translation termination in eukaryotes relies on release factors eRF1 and eRF3.
  • The exact mechanism of stop codon recognition by eRF1 is not fully understood, limiting drug development for translation termination defects.

Purpose of the Study:

  • To elucidate the structural basis of stop codon discrimination by human eRF1.
  • To investigate the role of the GTS loop in eRF1's specificity for stop codons.

Main Methods:

  • Solution structure determination of wild-type and mutant human eRF1 N-domain.
  • NMR analysis of eRF1 N-domain interaction with RNA mimics in a ribosomal complex.

Main Results:

  • The conserved GTS loop in eRF1 adopts different conformations, correlating with its stop codon recognition specificity (omnipotent vs. UGA-only).
  • eRF1's N-domain binds to RNA duplexes with internal loops, displacing the C-domain and suggesting domain rearrangement.
  • This rearrangement facilitates N-domain accommodation into the ribosomal A site.

Conclusions:

  • Structural variability in the eRF1 GTS loop underlies its ability to recognize all stop codons or specific ones.
  • eRF1 undergoes domain rearrangement for accommodation into the ribosomal A site during translation termination.
  • These findings provide a structural basis for understanding stop codon recognition and potential therapeutic targets.

More Related Videos

Xenopus laevis as a Model to Identify Translation Impairment10:24

Xenopus laevis as a Model to Identify Translation Impairment

Published on: September 27, 2015

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses11:19

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses

Published on: February 25, 2011

Related Concept Videos

Improving Translational Accuracy02:07

Improving Translational Accuracy

Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
Termination of Translation01:44

Termination of Translation

The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
Initiation of Translation02:33

Initiation of Translation

Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Initiation of Translation02:33

Initiation of Translation

Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Directing Proteins to the Rough Endoplasmic Reticulum01:34

Directing Proteins to the Rough Endoplasmic Reticulum

The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
Leaky Scanning02:28

Leaky Scanning

During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...