The molecule is a zwitterion obtained by transfer of a proton from the carboxy group to the cytidine ring of lysidine. Nucleoside used in tRNA Ile2 at position 34. Ensures the tRNA only charges Ile and not Met.
(2S)-2-amino-6-[[4-amino-1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]pyrimidin-1-ium-2-yl]amino]hexanoate