CRISPR–Cas13 systems use single-subunit RNA-guided Cas13 effectors for targeted RNA recognition and cleavage. This Review summarizes the recent advances in understanding the structural and mechanistic aspects of Cas13 systems and the diverse applications of these systems in biotechnology and therapeutics.

Sulfated compounds produced collaboratively by the microbiome and the host have important biological functions. This Review highlights the production of select sulfated carbohydrates, amino acid derivatives and steroidal metabolites and discusses their influence on health. The Review also explore potential roles of sulfated molecules in disease detection, prevention and treatment.

This Review provides an overview of different RNA base editing technologies, including the RNA-targeting platforms and modification effectors, with a focus on the emerging programmable RNA base editors and their potential in correcting pathological mutations.

Chemical approaches, such as those that leverage induced proximity, targeted degradation, synthetic gene regulators or protein design offer opportunities to therapeutically target cellular processes that have long been thought of as undruggable. We report on the progress and the potential for transformative collaborations between fields discussed at the 2023 Bringing Chemistry to Medicine symposium at St. Jude Children’s Research Hospital.

The kinesin-1 motor protein accesses open active and closed autoinhibited states. These states are regulated by a flexible elbow within a complex coiled-coil architecture. Now, a conformational switch has been developed by engineering the elbow to create a closed state that can be controllably opened with a de novo designed peptide to increase kinesin transport inside cells.

Toxic small alarmone synthetase (toxSAS) enzymes are toxic effectors of certain toxin–antitoxin modules, involved in phage defense and secretion systems. Here the authors establish the mechanism underlying toxSAS inhibition by structured antitoxins and reveal the connection between neutralization strategy and substrate specificity.

Enediyne natural products are potent antitumor antibiotics but the biosynthesis of their 1,5-diyne-3-ene core has remained enigmatic for decades. Here a diiodotetrayne is reported as a universal enediyne biosynthetic intermediate of this core, obtained upon cryptic iodination.

A de novo-designed protein that precisely assembles a chlorophyll dimer has been developed. The design matches the conformation of the native ‘special pair’ of chlorophylls that functions as the primary electron donor in natural photosynthetic reaction centers. In the designed protein, excitonically coupled chlorophylls participate in energy transfer. The proteins were also redesigned to assemble into 24-chlorophyll nanocages.

Jiang et al. developed a computational method to design repeat proteins with multiple structured loops that are buttressed by extensive hydrogen bond networks. The designs were further functionalized into high-affinity peptide-binding proteins.

Huang et al. report the tertiary structure of a small monomeric fluorogenic RNA aptamer named Clivia, characterized by a large Stokes shift, revealing the fluorescence activation mechanism and enabling a multivalent design to enhance the fluorescence output at specific dye concentrations.