Effects of G-quadruplex topology on translational inhibition by tRNA fragments in mammalian and plant systems in vitro

•tRNA fragments that fold into G-quadruplexes inhibit mammalian translation.•Efficiency of inhibition depends on the type of G-quadruplex topology.•G-quadruplex fold of a small RNA is not sufficient to inhibit plant translation. The folding of tRNA fragments (tRFs) into G-quadruplex structures and the implications of G-quadruplexes in translational inhibition have been studied mainly in mammalian systems. To increase our knowledge of these phenomena, we determined the influence of human and plant tRFs and model G-quadruplexes on translation in rabbit reticulocyte lysate and wheat germ extract. The efficiency of translational inhibition in the mammalian system was strongly associated with the type of G-quadruplex topology. In the plant system, the ability of a small RNA to adopt the G-quadruplex conformation was not sufficient to repress translation, indicating the importance of other structural determinants.