Formula C15H25N5O6 | Molar mass 371.39 g/mol | |
Lysidine is an uncommon nucleoside, rarely seen outside of tRNA. It is a derivative of cytidine in which the carbonyl is replaced by the amino acid lysine. The third position in the anti-codon of the Isoleucine-specific tRNA, is typically changed from a cytidine which would pair with guanosine to a lysidine which will base pair with adenosine. Uridine could not be used at this position even though it is a conventional partner for adenosine since it will also "wobble base pair" with guanosine. So lysidine allows better translation fidelity.
References
Lysidine (nucleoside) Wikipedia(Text) CC BY-SA