title: Pseudouridine formation in archaeal RNAs: The case of Haloferax volcanii.
abstract: Pseudouridine (Ψ), the isomer of uridine, is commonly found at various positions of noncoding RNAs of all organisms. Ψ residues are formed by a number of single- or multisite specific Ψ synthases, which generally act as stand-alone proteins. In addition, in Eukarya and Archaea, specific ribonucleoprotein complexes, each containing a distinct box H/ACA guide RNA and four core proteins, can produce Ψ at many sites of different cellular RNAs. Cbf5 is the core Ψ synthase in these complexes. Using Haloferax volcanii as an archaeal model organism, we show that, contrary to eukaryotes, the Cbf5 homolog (HVO_2493) is not essential in this archaeon. The Cbf5-deleted strain of H. volcanii completely lacks Ψ at positions 1940, 1942, 2605, and 2591 (Escherichia coli positions 1915, 1917, 2572, and 2586) of its 23S rRNA, and contains reduced steady-state levels of some box H/ACA RNAs. Archaeal Cbf5 is known to have tRNA Ψ55 synthase activity in vitro but we could not confirm this activity in vivo in H. volcanii. Conversely, the Pus10 (previously PsuX) homolog (HVO_1979), which can produce tRNA Ψ55, as well as Ψ54 in vitro, is shown here to be essential in H. volcanii, whereas the corresponding tRNA Ψ55 synthases, Pus4 and TruB, are not essential in yeast and E. coli, respectively. Finally, we demonstrate that HVO_1852, the TruA/Pus3 homolog, is responsible for the pseudouridylation of position 39 in H. volcanii tRNAs and that the corresponding gene is not essential.
authors.affiliation: Department of Microbiology & Cell Science, University of Florida, Gainesville, Florida 32611-0700, USA.
authors.forename: Ian K
authors.initials: IK
authors.lastname: Blaby
authors.forename: Mrinmoyee
authors.initials: M
authors.lastname: Majumder
authors.forename: Kunal
authors.initials: K
authors.lastname: Chatterjee
authors.forename: Sujata
authors.initials: S
authors.lastname: Jana
authors.forename: Henri
authors.initials: H
authors.lastname: Grosjean
authors.forename: Valérie
authors.initials: V
authors.lastname: de Crécy-Lagard
authors.forename: Ramesh
authors.initials: R
authors.lastname: Gupta
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D017353:Gene Deletion; D019622:Haloferax volcanii / Q000235:genetics* / Q000378:metabolism*; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011560:Pseudouridine / Q000378:metabolism*; D019642:RNA, Archaeal / Q000378:metabolism*
chemical_list: D019642:RNA, Archaeal; D011560:Pseudouridine; D006836:Hydro-Lyases; D019751:Intramolecular Transferases; C096995:pseudouridine synthases; D000604:Amino Acyl-tRNA Synthetases