Lysidine (nucleoside)

Lysidine (nucleoside)
IUPAC name 2-Amino-6-[4-amino-1-(3,4-dihydroxy-5-hydroxymethyloxolan-2-yl)-1H-pyrimidin-2-ylideneamino]hexanoic acid
Other names 4-Amino-2-(N(6)-lysino)-1-ribofuranosylpyrimidine
Identifiers
CAS number	144796-96-3 Y
PubChem	44124149
	Jmol-3D images	{{#if:OC[C@H]1O[C@@H](N2C=CC(N)=N/C2=N\CCCC[C@H](N)C(O)=O)[C@H](O)[C@@H]1O|Image 1
SMILES OC[C@H]1O[C@@H](N2C=CC(N)=N/C2=N\CCCC[C@H](N)C(O)=O)[C@H](O)[C@@H]1O
Properties
Molecular formula	C15H25N5O6
Molar mass	371.39 g/mol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

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.^[1][2]

Lysidine base pairs with Adenosine in context of a Cytosine to Guanosine base pair. R = ribose. Arrows indicate hydrogen bonds going from hydrogens to bond acceptor. The notation for lysidine, L, is depicted above.

References