Chemical synthesis of the 5-taurinomethyl(-2-thio)uridine modified anticodon arm of the human mitochondrial tRNA(Leu(UUR)) and tRNA(Lys).
5-Taurinomethyluridine (τm(5)U) and 5-taurinomethyl-2-thiouridine (τm(5)s(2)U) are located at the wobble position of human mitochondrial (hmt) tRNA(Leu(UUR)) and tRNA(Lys), respectively. Both hypermodified units restrict decoding of the third codon letter to A and G. Pathogenic mutations in the genes encoding hmt-tRNA(Leu(UUR)) and hmt-tRNA(Lys) are responsible for the loss of the discussed modifications and, as a consequence, for the occurrence of severe mitochondrial dysfunctions (MELAS, MERRF). Synthetic oligoribonucleotides bearing modified nucleosides are a versatile tool for studying mechanisms of genetic message translation and accompanying pathologies at nucleoside resolution. In this paper, we present site-specific chemical incorporation of τm(5)U and τm(5)s(2)U into 17-mers related to the sequence of the anticodon arms hmt-tRNA(Leu(UUR)) and hmt-tRNA(Lys), respectively employing phosphoramidite chemistry on CPG support. Selected protecting groups for the sulfonic acid (4-(tert-butyldiphenylsilanyloxy)-2,2-dimethylbutyl) and the exoamine function (-C(O)CF3) are compatible with the blockage of the canonical monomeric units. The synthesis of τm(5)s(2)U-modified RNA fragment was performed under conditions eliminating the formation of side products of 2-thiocarbonyl group oxidation and/or oxidative desulphurization. The structure of the final oligomers was confirmed by mass spectroscopy and enzymatic cleavage data.
Institute of Organic Chemistry, Lodz University of Technology, 90-924 Lodz, Poland.
Grazyna
G
Leszczynska
Institute of Organic Chemistry, Lodz University of Technology, 90-924 Lodz, Poland.
Piotr
P
Leonczak
Institute of Organic Chemistry, Lodz University of Technology, 90-924 Lodz, Poland.
Karolina
K
Wozniak
Institute of Organic Chemistry, Lodz University of Technology, 90-924 Lodz, Poland.
Andrzej
A
Malkiewicz
D000926:Anticodon / Q000235:genetics*; D006801:Humans; D008928:Mitochondria / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides / Q000235:genetics; D012356:RNA, Transfer, Leu / Q000235:genetics*; D012357:RNA, Transfer, Lys / Q000235:genetics*; D013891:Thiouridine / Q000031:analogs & derivatives* / Q000138:chemical synthesis
C540247:5-taurinomethyl-2-thiouridine; D000926:Anticodon; D009843:Oligoribonucleotides; D012356:RNA, Transfer, Leu; D012357:RNA, Transfer, Lys; D013891:Thiouridine
5-taurinomethyl-2-thiouridine; 5-taurinomethyluridine; human mitochondrial tRNA; modified ribonucleosides; phosphoramidite chemistry