Fig. 1

5ʹTOG containing tiRNAs exist in two distinct and interconvertible forms. a G-quartet formation by guanines. b Predicted secondary structure of 5ʹtiRNA^Ala with a predominant hairpin structure. 5ʹTOG motif is indicted in green. c Indicated RNAs were ran on a 15% acrylamide denaturing gel (left panels) or native gel (right panels). Gels were post-stained with either SYBR gold to detect total RNA or NMM to detect RG4 structures. 5ʹtiRNA^Ala ran at the expected 31 nts, but also at ~120 nts. Only the more slowly running band stained with NMM, indicating it contained RG4s. This more slowly migrating band persisted under denaturing conditions. d Indicated 5ʹtiRNAs were ran on a 15% denaturing acrylamide gel and either upper or lower species were gel purified and reanalysed on a denaturing acrylamide gel and post-stained with SYBR gold. A portion of the lower band re-equilibrated to the upper band and vice-a-versa. e 5ʹtiRNA^Ala was equilibrated overnight in 100 mM of indicated salts. RNAs were analyzed on denaturing (left panels) or native gels (right panels) and post-stained with SYBR gold or NMM. Results demonstrate that NMM staining, more slowly migrating band disassembles in the presence of Li⁺ ions