Ribozyme

A ribozyme is a polyribonucleotide (RNA molecule) with enzymatic activity. They are sometimes also referred to as "RNA enzymes" however, because this term can lead to some confusion in distinguishing them from ribonucleoproteins (proteins that contain RNA), "ribozyme" is preferred.

Ribozymes are found in every known cell and are essential to cell functioning. The most well known example of an essential ribozyme is the 28S rRNA (called the 23S rRNA in prokaryotes), which carries out the aminoacyltransferase (peptide-lengthening) activity of ribosomes.