Pseudouridine synthase

Pseudouridine is an abundant modified nucleoside found in RNA molecules. It is formed post-transcriptionally in RNA molecules by isomerization of the bond between base and ribose in uridine. There are two major types of enzymes that catalyze this reaction:

• RNA-guided pseudouridine synthase -- Some ribonucleoproteins (complexes of proteins and small RNAs) have been identified in archaea and eukaryotes to catalyze these reactions. The small RNA in the complex serves as a guide element to select the site of modification through base-pairing with the target RNA molecule.

• Guide-independent pseudouridine synthase -- The alternative to using the RNA-guided mechanism for pseudouridine formation is a guide-independent mechanism acting through protein-only enzymes to catalyze the isomerization.

Structural highlights

The conversion of uridine to pseudouridine is accompanied by a conformational change of pseudouridine synthase^[1]. (1ze2).