Synthesis and Structure Elucidation of Glutamyl-Queuosine
Alexander Pichler, Markus Hillmeier, Matthias Heiß, Elsa Peev, Stylianos Xefteris, Barbara Steigenberger, Ines Thoma, Markus Müller, Marco Borsò, Axel Imhof, Thomas Carell
Abstract
High Resolution Image Download MS PowerPoint Slide Queuosine is one of the most complex hypermodified RNA nucleosides found in the Wobble position of tRNAs. In addition to Queuosine itself, several further modified derivatives are known, where the cyclopentene ring structure is additionally modified by a galactosyl-, a mannosyl-, or a glutamyl-residue. While sugar-modified Queuosine derivatives are found in the tRNAs of vertebrates, glutamylated Queuosine (gluQ) is only known in bacteria. The exact structure of gluQ, particularly with respect to how and where the glutamyl side chain is connected to the Queuosine cyclopentene side chain, is unknown. Here we report the first synthesis of gluQ and, using UHPLC-MS- co injection and NMR studies, we show that the isolated natural gluQ is the α-allyl-connected gluQ compound.