Ribozymes are naturally occurring RNA catalytic molecules that are able to promote biochemical reactions, mostly in gene expression and RNA processing. Ribozymes work autonomously or in ribonucleoprotein complexes, different from conventional protein enzymes. In the 1980s, they were discovered, and this offered proof that RNA can function both as a catalyst and as genetic material, affirming the "RNA World" hypothesis. Examples include the hammerhead ribozyme, introns group I and II, and the peptidyl transferase center of the ribosome, an important site involved in protein synthesis.
These RNA catalysts play critical roles in biological processes, catalyzing self-splicing intron excision, RNA cutting, and joining. Certain ribozymes manage gene expression through regulation of mRNA stability and translation. In addition to their endogenous functions, ribozymes are of interest in biotechnological and therapeutic applications, such as gene editing and antiviral therapy. The discovery of ribozymes revolutionized the field of molecular biology, highlighting RNA's versatility and its central function in the early evolution of life. Engineered ribozymes are under investigation for use in synthetic biology and medicine.