 Pseudouridine, being one of them, is the C5-glycoside isomer of uridine that contains a C-C bond between C1 of the ribose sugar and C5 of uracil, rather than usual C1-N1 bond found in uridine.The C-C bond gives it more rotational freedom and conformational flexibility.In addition, pseudouridine has an extra hydrogen bond donor at the N1 position.