Description
Pseudouridine (Ψ) 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. Ψ is derived from uridine (U) via base-specific isomerization catalyzed by Ψ 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, Ψ 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 Ψ, which could contribute to subsequent cellular functions.