title: Identification of the enzyme responsible for N1-methylation of pseudouridine 54 in archaeal tRNAs.
abstract: tRNAs from all three kingdoms of life contain a variety of modified nucleotides required for their stability, proper folding, and accurate decoding. One prominent example is the eponymous ribothymidine (rT) modification at position 54 in the T-arm of eukaryotic and bacterial tRNAs. In contrast, in most archaea this position is occupied by another hypermodified nucleotide: the isosteric N1-methylated pseudouridine. While the enzyme catalyzing pseudouridine formation at this position is known, the pseudouridine N1-specific methyltransferase responsible for this modification has not yet been experimentally identified. Here, we present biochemical and genetic evidence that the two homologous proteins, Mja_1640 (COG 1901, Pfam DUF358) and Hvo_1989 (Pfam DUF358) from Methanocaldococcus jannaschii and Haloferax volcanii, respectively, are representatives of the methyltransferase responsible for this modification. However, the in-frame deletion of the pseudouridine N1-methyltransferase gene in H. volcanii did not result in a discernable phenotype in line with similar observations for knockouts of other T-arm methylating enzymes.
authors.affiliation: Institut für Molekulare Biowissenschaften, Johann-Wolfgang-Goethe-Universität, 60438 Frankfurt/M., Germany.
authors.forename: Jan Philip
authors.initials: JP
authors.lastname: Wurm
authors.forename: Marco
authors.initials: M
authors.lastname: Griese
authors.forename: Ute
authors.initials: U
authors.lastname: Bahr
authors.forename: Martin
authors.initials: M
authors.lastname: Held
authors.forename: Alexander
authors.initials: A
authors.lastname: Heckel
authors.forename: Michael
authors.initials: M
authors.lastname: Karas
authors.forename: Jörg
authors.initials: J
authors.lastname: Soppa
authors.forename: Jens
authors.initials: J
authors.lastname: Wöhnert
mesh_terms: D000595:Amino Acid Sequence; D001105:Archaea / Q000201:enzymology* / Q000235:genetics*; D020029:Base Pairing; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism; D055786:Gene Knockout Techniques; D019622:Haloferax volcanii / Q000235:genetics / Q000378:metabolism; D017015:Methanococcales / Q000235:genetics / Q000378:metabolism; D008745:Methylation; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D011487:Protein Conformation; D011560:Pseudouridine / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D012359:tRNA Methyltransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D011560:Pseudouridine; D012343:RNA, Transfer; D012359:tRNA Methyltransferases; C409038:nucleus-encoded phage-type RNA polymerase; D012321:DNA-Directed RNA Polymerases