Skip to content
Login Register

#large subunit

2 public questions tagged with this topic.

Processing of rRNA and tRNA

The 5.8S rRNA associates with

Eukaryotic large subunit contains three rRNAs: 28S, 5.8S and 5S. 5.8S rRNA, about 160 nucleotides, is structurally homologous to 5' end of bacterial 23S rRNA and extensively base-pairs with 28S rRNA through complementary sequences, forming a stable helix that anchors 5.8S near peptidyl transferase center and the polypeptide exit tunnel. This association is essential for 60S assembly, stability and interaction with ribosomal proteins L23 and others. 18S belongs to small subunit, 5S binds separately at central protuberance. This refined regulation supports accurate ribosomal assembly, quality control and translational fidelity under diverse physiological conditions and growth states.

Ref: Lodish et al., Molecular Cell Biology, 9th ed., Chapter 8, Association of eukaryotic 5.8S with 28S rRNA

View Details
Processing of rRNA and tRNA

Which rRNA is part of large subunit in prokaryotes?

The bacterial 70S ribosome consists of 30S small subunit and 50S large subunit. The large subunit comprises 23S rRNA of about 2900 nucleotides and 5S rRNA plus 33 ribosomal proteins. 23S rRNA dominates the particle, forming peptidyl transferase center in domain V, nascent peptide exit tunnel lining, and intersubunit bridges. 16S rRNA is confined to small subunit for decoding. Therefore, 23S marks the large subunit, whereas 16S marks small subunit. Eukaryotic counterpart is 28S rRNA in 60S, underscoring evolutionary conservation of large subunit catalytic RNA.

Ref: Watson Molecular Biology of the Gene, 7th ed., Chapter 15, Bacterial 50S subunit and 23S rRNA

View Details