The largest ribonucleoprotein component of RIBOSOMES. It contains the domains which catalyze formation of the peptide bond and translocation of the ribosome along the MESSENGER RNA during GENETIC TRANSLATION.

Synonyms: Ribosomal Subunits, Large Subunits, Large Ribosomal Large Ribosomal Subunits Subunit, Large Ribosomal Large Ribosome Subunit Ribosome Subunit, Large Large Ribosomal Subunit Subunits, Large Ribosome Large Ribosome Subunits Ribosome Subunits, Large Subunit, Large Ribosome Ribosomal Subunit, Large