title: In vitro substrate specificities of 3'-5' polymerases correlate with biological outcomes of tRNA 5'-editing reactions.
abstract: Protozoan mitochondrial tRNAs (mt-tRNAs) are repaired by a process known as 5'-editing. Mt-tRNA sequencing revealed organism-specific patterns of editing G-U base pairs, wherein some species remove G-U base pairs during 5'-editing, while others retain G-U pairs in the edited tRNA. We tested whether 3'-5' polymerases that catalyze the repair step of 5'-editing exhibit organism-specific preferences that explain the treatment of G-U base pairs. Biochemical and kinetic approaches revealed that a 3'-5' polymerase from Acanthamoeba castellanii tolerates G-U wobble pairs in editing substrates much more readily than several other enzymes, consistent with its biological pattern of editing.
authors.affiliation: Department of Chemistry and Biochemistry, Center for RNA Biology and Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, United States.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Long
authors.affiliation: Department of Chemistry and Biochemistry, Center for RNA Biology and Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, United States. Electronic address: jackman.14@osu.edu.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Jackman
mesh_terms: D048248:Acanthamoeba castellanii / Q000201:enzymology* / Q000378:metabolism; D004023:Dictyostelium / Q000201:enzymology / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D007553:Isotope Labeling; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology* / Q000378:metabolism; D008958:Models, Molecular; D010761:Phosphorus Radioisotopes; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D017393:RNA Editing; D012316:RNA Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D016053:RNA, Protozoan / Q000737:chemistry / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D012355:RNA, Transfer, Ile / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013045:Species Specificity; D013379:Substrate Specificity
chemical_list: D007527:Isoenzymes; D010761:Phosphorus Radioisotopes; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D012355:RNA, Transfer, Ile; D011994:Recombinant Proteins; D012343:RNA, Transfer; D012316:RNA Nucleotidyltransferases; C023198:tRNA nucleotidyltransferase
keywords: 3′–5′ polymerase; Acanthamoeba castellanii; Dictyostelium discoideum; Mitochondrial tRNA; Thg1-like protein; tRNA editing