4thiouridinebased

4thiouridine is a modified nucleoside that is a derivative of uridine. In this molecule, the oxygen atom at the 4-position of the uracil base is replaced by a sulfur atom. This substitution significantly alters the electronic and chemical properties of the nucleoside. Specifically, the presence of sulfur makes 4thiouridine more susceptible to photochemical reactions, particularly when exposed to ultraviolet (UV) light.

This photosensitivity has made 4thiouridine a valuable tool in molecular biology research. When incorporated into RNA, it can be used to study RNA-protein interactions and RNA structure. Upon UV irradiation, 4thiouridine can form covalent cross-links with nearby amino acid residues in proteins that are in close proximity to the RNA. These cross-links can then be detected and analyzed to map the sites of interaction. This technique, known as photo-crosslinking, has been instrumental in understanding how RNA molecules function within cells, including their roles in gene regulation, translation, and RNA processing. Furthermore, 4thiouridine has been investigated for its potential therapeutic applications, particularly in the field of photodynamic therapy.