ribozimek

Ribozyme, sometimes rendered as ribozimek in certain languages, is an RNA molecule capable of catalyzing specific chemical reactions. Unlike most enzymes, which are proteins, ribozymes are RNA-based catalysts. They participate in RNA processing and metabolism, including RNA splicing, tRNA maturation, and viral replication.

Ribozymes were discovered in the late 20th century, notably by Thomas Cech and colleagues, whose work showed that RNA can have enzymatic activity. The discovery of self-splicing introns and the RNase P RNA component demonstrated that RNA alone can act as a catalyst, providing support for the RNA world hypothesis.

Notable examples include self-splicing introns (group I and group II), hammerhead ribozyme, hairpin ribozyme, and glmS ribozyme. These molecules catalyze reactions such as RNA strand cleavage and ligation at defined sites, often without the need for protein enzymes. Some ribozymes act in ribonucleoprotein complexes, where protein cofactors assist or regulate RNA catalysis.

Mechanistically, ribozymes fold into complex three-dimensional structures that create an active site. Many depend on divalent metal ions, particularly magnesium, which can stabilize negative charges or participate directly in catalysis. The activity and specificity of ribozymes are influenced by sequence, structure, and folding conditions.

Applications in biotechnology and medicine include using ribozymes for targeted RNA cleavage and gene regulation, as well as serving as tools in research and potential therapeutic agents. In origins-of-life research, ribozymes illustrate how RNA could have carried both genetic information and catalytic function. Limitations include variable catalytic efficiency and stability in different environments, guiding ongoing efforts to engineer improved ribozymes.