Lysidine (nucleoside)
Encyclopedia
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.
Nucleoside
Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar via a beta-glycosidic linkage...
, rarely seen outside of tRNA. It is a derivative of cytidine
Cytidine
Cytidine is a nucleoside molecule that is formed when cytosine is attached to a ribose ring via a β-N1-glycosidic bond...
in which the carbonyl is replaced by the amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
lysine
Lysine
Lysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
. The third position in the anti-codon of the Isoleucine-specific tRNA, is typically changed from a cytidine which would pair with guanosine
Guanosine
Guanosine is a purine nucleoside comprising guanine attached to a ribose ring via a β-N9-glycosidic bond. Guanosine can be phosphorylated to become guanosine monophosphate , cyclic guanosine monophosphate , guanosine diphosphate , and guanosine triphosphate...
to a lysidine which will base pair
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
with adenosine. Uridine
Uridine
Uridine is a molecule that is formed when uracil is attached to a ribose ring via a β-N1-glycosidic bond.If uracil is attached to a deoxyribose ring, it is known as a deoxyuridine....
could not be used at this position even though it is a conventional partner for adenosine since it will also "wobble base pair
Wobble base pair
In molecular biology, a wobble base pair is a non-Watson-Crick base pairing between two nucleotides in RNA molecules. The four main wobble base pairs are guanine-uracil, inosine-uracil, inosine-adenine, and inosine-cytosine . The thermodynamic stability of a wobble base pair is comparable to that...
" with guanosine. So lysidine allows better translation fidelity.