title: Two-subunit enzymes involved in eukaryotic post-transcriptional tRNA modification.
abstract: tRNA modifications are crucial for efficient and accurate protein translation, with defects often linked to disease. There are 7 cytoplasmic tRNA modifications in the yeast Saccharomyces cerevisiae that are formed by an enzyme consisting of a catalytic subunit and an auxiliary protein, 5 of which require only a single subunit in bacteria, and 2 of which are not found in bacteria. These enzymes include the deaminase Tad2-Tad3, and the methyltransferases Trm6-Trm61, Trm8-Trm82, Trm7-Trm732, and Trm7-Trm734, Trm9-Trm112, and Trm11-Trm112. We describe the occurrence and biological role of each modification, evidence for a required partner protein in S. cerevisiae and other eukaryotes, evidence for a single subunit in bacteria, and evidence for the role of the non-catalytic binding partner. Although it is unclear why these eukaryotic enzymes require partner proteins, studies of some 2-subunit modification enzymes suggest that the partner proteins help expand substrate range or allow integration of cellular activities.
authors.affiliation: a Department of Biochemistry and Biophysics; Center for RNA Biology ; University of Rochester School of Medicine ; Rochester , NY USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Guy
authors.forename: Eric M
authors.initials: EM
authors.lastname: Phizicky
mesh_terms: D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009700:Nucleoside Deaminases / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012359:tRNA Methyltransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D012343:RNA, Transfer; D012359:tRNA Methyltransferases; D009700:Nucleoside Deaminases
keywords: Tad2; Trm112; Trm61; Trm7; Trm734; Trm8; Trm9; cerevisiae; modification; tRNA