Ribozymes play catalytic roles in diverse biochemical processes. Group II (GII) intron ribozymes are well-studied catalysts for splicing and retrotransposition with the assistance of intron-encoded proteins (IEPs) through transesterification. When IEPs are not provided, GII introns can cleave their precursor RNA targets through hydrolysis, forming mature and linearized ribozymes. These ribozymes also exhibit hydrolytic endonuclease activity on RNA or DNA-modified RNA substrates. However, substantive hydrolytic cleavage of pure DNA is rarely observed within reported intron ribozymes. These clues suggest that uncharacterized intron ribozymes encoded by “propagating” retrotransposons, especially those that naturally lack the IEP components [open reading frame (ORF)–less introns], might hold the potential to cleave pure DNA targets through hydrolysis. These hypothetical ribozymes are called HYdrolytic Endonucleolytic Ribozymes (HYERs). If available, RNA-based HYERs could be employed for gene editing, expanding the current toolbox established by protein enzymes such as TALEN and CRISPR-Cas. Here you can see a cryoEM structure of the Anoxybacillus pushchinoensis ORF-less Group IIC Intron HYER1 (PDB code: 8K0S)

#molecularart #ribozyme #dnazyme #editing #anoxybacillus #cryoem

Structure rendered with @proteinimaging, post-processed with @stylar.ai_official and depicted with @corelphotopaint