Chemical compounds corresponding to Pseudouridine / 5-ribosyluracil.
Pseudouridine (psi) was among the first post-transcriptional modifications discovered and is overall one of the most abundant(1). It is present in a wide range of cellular RNAs and is highly conserved across species. psi is derived from uridine (U) via base-specific isomerization catalyzed by psi synthases. The site-specific pseudouridylation goes through either snoRNA-dependent (requires H/ACA RNP) or -independent mechanism (requires pseudouridine synthase (PUS) family enzymes)(2). It has an extra hydrogen-bond donor at its non-Watson-Crick edge. When incorporated into RNA, psi can alter RNA secondary structure by increasing base stacking, improving base pairing and rigidifying sugar-phosphate backbone5. The chemical and physical properties of RNA can be altered with the incorporation of psi, which could contribute to subsequent cellular functions.
