title: Chimeric human mitochondrial PheRS exhibits editing activity to discriminate nonprotein amino acids.
abstract: Mitochondria are considered as the primary source of reactive oxygen species (ROS) in nearly all eukaryotic cells during respiration. The harmful effects of these compounds range from direct neurotoxicity to incorporation into proteins producing aberrant molecules with multiple physiological problems. Phenylalanine exposure to ROS produces multiple oxidized isomers: tyrosine, Levodopa, ortho-Tyr, meta-Tyr (m-Tyr), and so on. Cytosolic phenylalanyl-tRNA synthetase (PheRS) exerts control over the translation accuracy, hydrolyzing misacylated products, while monomeric mitochondrial PheRS lacks the editing activity. Recently we showed that "teamwork" of cytosolic and mitochondrial PheRSs cannot prevent incorporation of m-Tyr and l-Dopa into proteins. Here, we present human mitochondrial chimeric PheRS with implanted editing module taken from EcPheRS. The monomeric mitochondrial chimera possesses editing activity, while in bacterial and cytosolic PheRSs this type of activity was detected for the (αβ)2 architecture only. The fusion protein catalyzes aminoacylation of tRNA(Phe) with cognate phenylalanine and effectively hydrolyzes the noncognate aminoacyl-tRNAs: Tyr-tRNA(Phe) and m-Tyr-tRNA(Phe) .
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel.
authors.forename: Ekaterine
authors.initials: E
authors.lastname: Kartvelishvili
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Peretz
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Tworowski
authors.affiliation: Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, 630090, Russia.
authors.forename: Nina
authors.initials: N
authors.lastname: Moor
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel.
authors.forename: Mark
authors.initials: M
authors.lastname: Safro
mesh_terms: D000215:Acylation; D000596:Amino Acids / Q000378:metabolism*; D003001:Cloning, Molecular; D006801:Humans; D006868:Hydrolysis; D008928:Mitochondria / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D010649:Phenylalanine / Q000378:metabolism; D010652:Phenylalanine-tRNA Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000596:Amino Acids; D012346:RNA, Transfer, Amino Acyl; D017382:Reactive Oxygen Species; D011993:Recombinant Fusion Proteins; D010649:Phenylalanine; D010652:Phenylalanine-tRNA Ligase
keywords: ROS-damaged amino acid; aminoacyl-tRNA synthetases; aminoacylation; chimera; editing; fusion protein