Elucidating Evolutionary Mechanisms and Variants of the Hammerhead Ribozyme Using In Vitro Selection.

The Hammerhead Ribozyme (HHR) is a ubiquitous RNA enzyme that catalyzes site-specific intramolecular cleavage. While mutations to its catalytic core have traditionally been viewed as detrimental to its activity, several discoveries of naturally occurring variants of the full-length ribozyme challenge this notion, suggesting a deeper understanding of HHR evolution and functionality. By systematically introducing mutations at key nucleotide positions within the catalytic core, we generated single-, double-, and triple-mutation libraries to explore the sequence requirements and evolution of a full-length HHR.

Development of Better Aptamers: Structured Library Approaches, Selection Methods, and Chemical Modifications.

Systematic evolution of ligands by exponential enrichment (SELEX) has been used to discover thousands of aptamers since its development in 1990. Aptamers are short single-stranded oligonucleotides capable of binding to targets with high specificity and selectivity through structural recognition. While aptamers offer advantages over other molecular recognition elements such as their ease of production, smaller size, extended shelf-life, and lower immunogenicity, they have yet to show significant success in real-world applications.