Composed of 2 subunits: large ribosomal subunit and small ribosomal subunit, both composed of rRNA (ribosomal RNA)
mRNA moves through groove between subunits
Contains 3 binding sites
Occurs when stop codons enter the A site (UAA, UAG, UGA)
Protein release factor binds instead of aminoacyl-tRNA (there are no corresponding amino acids for stop codons)
Polypeptide is released, ribosomal subunits detach.