Lysidine (nucleoside)

Lysidine (nucleoside)

Names
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
3D model (Jmol)	Interactive image
ChemSpider	24604124
PubChem	44124149
InChI InChI=1S/C15H25N5O6/c16-8(14(24)25)3-1-2-5-18-15-19-10(17)4-6-20(15)13-12(23)11(22)9(7-21)26-13/h4,6,8-9,11-13,21-23H,1-3,5,7,16H2,(H,24,25)(H2,17,18,19)/t8-,9+,11+,12+,13+/m0/s1 Key: MDWUIKMWKDMPDE-IINAIABHSA-N
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
Chemical formula	C15H25N5O6
Molar mass	371.39 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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

1. Nakanishi K, Fukai S, Ikeuchi Y, et al. (May 2005). "Structural basis for lysidine formation by ATP pyrophosphatase accompanied by a lysine-specific loop and a tRNA-recognition domain". Proc. Natl. Acad. Sci. U.S.A. 102 (21): 7487–7492. doi:10.1073/pnas.0501003102. PMC 1140429. PMID 15894617.
2. Salowe SP, Wiltsie J, Hawkins JC, Sonatore LM (Apr 10, 2009). "The Catalytic Flexibility of tRNAIle-lysidine Synthetase Can Generate Alternative tRNA Substrates for Isoleucyl-tRNA Synthetase". J Biol Chem. 284 (15): 9656–9662. doi:10.1074/jbc.M809013200. PMC 2665086. PMID 19233850.