A minor species of isoleucine tRNA (tRNA(minor)(Ile)) specific to the codon AUA has been isolated from Escherichia coli B and a modified nucleoside N+ has been found in the first position of the anticodon (Harada, F., and Nishimura, S. (1974) Biochemistry 13, 300-307). In the present study, tRNA(minor)(Ile) was purified from E. coli A19, and nucleoside N+ was prepared, by high-performance liquid chromatography, in an amount (0.6 A260 units) sufficient for the determination of chemical structures. By 400 MHz 1H NMR analysis, nucleoside N+ was found to have a pyrimidine moiety and a lysine moiety, the ε-amino group of which was involved in the linkage between these two moieties. From the NMR analysis together with mass spectrometry, the structure of nucleoside N+ was determined as 4-amino-2-(N6-lysino)-1-(β-D-ribofuranoysl)pyrimidinium ('lysidine'), which was confirmed by chemical synthesis. Lysidine is a novel type of modified cytidine with a lysine moiety and has one positive charge. Probably because of such a unique structure, lysidine in the first position of anticodon recognizes adenosine but not guanosine in the third position of codon.
|ジャーナル||Journal of Biological Chemistry|
|出版ステータス||Published - 1988|
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