This group consists of eukaryotic and archeal pseudouridine synthases similar to human dyskerin, Saccharomyces cerevisiae Cbf5, and Drosophila melanogaster Mfl (minifly protein). Pseudouridine synthases catalyze the isomerization of specific uridines in an RNA molecule to pseudouridines (5-ribosyluracil, psi). No cofactor is required. S. cerevisiae Cbf5 and human dyskerin are nucleolar proteins that, with the help of guide RNAs, make the hundreds of psueudouridnes present in rRNA and small nuclear RNAs (snRNAs). Cbf5/Dyskerin is the catalytic subunit of eukaryotic box H/ACA small nucleolar ribonucleoprotein (snoRNP) particles. D. melanogaster mfl hosts in its fourth intron, a box H/AC snoRNA gene. In addition dyskerin is likely to have a structural role in the telomerase complex. Mutations in human dyskerin cause X-linked dyskeratosis congenitas. Mutations in Drosophila Mfl results in miniflies that suffer abnormalities.
Jiyao W et al.(2023). "The conserved domain database in 2023.",