Catalytic RNA articles from across Nature Portfolio

Although the Tetrahymena group I intron was the first RNA catalyst discovered, important mechanistic details remain ambiguous. Now six different conformational states of Tetrahymena group I intron self-splicing and an unexpected pseudoknotted structure are resolved by cryogenic electron microscopy.

Ribosomes have evolved to polymerize L-α-amino acids into proteins comprising a peptide backbone. Here, a pyridazinone backbone is formed using ribosomes in vitro, producing a variety of sequence-defined alternating block-copolymers.

Ribonuclease P efficiently processes all tRNA precursors despite sequence variation at the site of cleavage. Here, authors use high-throughput enzymology and cryoEM to reveal conformational changes that drive recognition by bacterial RNase P.

Complex biochemical systems exhibit traits that appear to be highly adapted. Studies of catalytic RNA demonstrate that adaptive traits, such as increased specificity and error tolerance, could originate as evolutionary by-products.

Ribozymes that use the cellular cofactor S-adenosyl-l-methionine to methylate RNA remained elusive. Now, such a ribozyme is reported by identifying natural sequences that are active in vitro; and crystal structures of the ribozyme with and without the cofactor are determined.

Site-specific modification of RNA in cells is crucial for analysis and functional investigations. Natural enzymes that promote RNA methylation using S-adenosyl-l-methionine (SAM) exist, but leveraging these proteins for RNA modification is limited by cell permeability, stability and specificity of their substrates. Now, a de novo ribozyme that acts on a stabilized and cell-permeable SAM analogue enables site-specific RNA modification with a click handle in living cells.

The discovery of the Tetrahymena group I intron’s self-splicing defined RNAs as capable catalysts. Now, cryogenic electron microscopy structures of this ribozyme have revealed large conformational changes and mechanistic details of its two-step mode of action.

Of the few known catalytic RNAs in biology, all but the ribosome involve reactions with phosphodiester bonds. Now, a ribozyme that catalyses a completely different reaction was discovered in all three domains of life.