A<unk>  (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule that catalyzes a chemical reaction. Many natural<unk> s catalyze either the hydrolysis of one of their own phosphodiester bonds, or the hydrolysis of bonds in other RNAs, but they have also been found to catalyze the aminotransferase activity of the ribosome.
Investigators studying the origin of life have produced<unk> s in the laboratory that are capable of catalyzing their own synthesis under very specific conditions, such as an RNA polymerase<unk> . Mutagenesis and selection has been performed resulting in isolation of improved variants of the "Round-18" polymerase<unk>  from 2001. "B6.61" is able to add up to 20 nucleotides to a primer template in 24 hours, until it decomposes by hydrolysis of its phosphodiester bonds.
Ribozyme
Electron shell
RNA polymerase
Ribosomal RNA
Macrocycle
Sarcomere
Viral envelope
Transfer RNA