Pseudouridine synthase

Function

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

• RNA-guided Pseudoridine synthase -- 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 specify 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 stand-alone enzymes to catalyze formation.

Structural highlights

The conversion of uridine to pseudouridine causes conformational change of PUS^[1]. (1ze2).