Members of this family are involved in modifying bases in RNA molecules. They carry out the conversion of uracil bases to pseudouridine. This family includes RluD Swiss:P33643, a pseudouridylate synthase that converts specific uracils to pseudouridine in 23S rRNA. RluA from E. coli converts bases in both rRNA and tRNA [1].

1: A dual-specificity pseudouridine synthase: an Escherichia coli synthase purified and cloned on the basis of its specificity for psi 746 in 23S RNA is also specific for psi 32 in tRNA(phe). Wrzesinski J, Nurse K, Bakin A, Lane BG, Ofengand J; RNA 1995;1:437-448. PMID:7493321