Eukaryotic ribosomal decoding center (DC)

The eukaryotic ribosomal decoding center is a highly conserved functional site within the 40S (small) ribosomal subunit that plays a pivotal role in ensuring the fidelity of protein synthesis (Prokhorova et al., 2017). It is primarily composed of specific regions of the 18S ribosomal RNA (rRNA), including the universally conserved adenine residues A1824 and A1825 (human numbering), which monitor the complementarity between the mRNA codon and the tRNA anticodon at the aminoacyl (A) site (Lynch and Puglisi, 2001). When a correct codon-anticodon match occurs, these residues undergo a conformational change that stabilizes the interaction and triggers the GTPase activity of elongation factors, allowing translation to proceed. While this site is a classic target for aminoglycoside antibiotics in bacteria, it has become a significant therapeutic target in humans for treating genetic diseases caused by premature termination codons (PTCs), such as cystic fibrosis and Duchenne muscular dystrophy (Ng and Steitz, 2014). Small molecules like ataluren and ELX-02 bind to the decoding center to reduce its stringency, thereby promoting "translational read-through" where a near-cognate tRNA is inserted at a stop codon, restoring the production of functional, full-length proteins (Fan-Minogue et al., 2013). However, the therapeutic window is narrow, as excessive interference with decoding can lead to global translational errors, and many agents show off-target toxicity due to their similarity to the mitochondrial ribosomal decoding site.

Other names

40S decoding site18S rRNA decoding regionEukaryotic 80S ribosome decoding centerA-site decoding centerRibosomal A-site

Induction of translational read-through of premature termination codons (PTCs) by decreasing the stringency of the decoding process at the ribosomal A-site.