Practice question

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.