0000000000236319
AUTHOR
Kenneth C. Kuo
Presence of phosphorylatedO-ribosyl-adenosine In T-ψ-stem of yeast methlonine initiator tRNA
We report in this paper on isolation and characterization of two unknown nucleosides G* and [A*] located in the T-psi-stem of yeast methionine initiator tRNA, using the combined means of HPLC protocols, real time UV-absorption spectrum, and post-run mass spectrometry by electron impact or fast atom bombardment. The G* nucleoside in position 65 was identified as unmodified guanosine. The structure of the unknown [A*] in position 64 was characterized as an isomeric form of O-ribosyl-adenosine by comparison of its chromatographic, UV-spectral and mass spectrometric properties with those of authentic O-alpha-ribofuranosyl-(1"----2')-adenosine isolated from biosynthetic poly(adenosine diphosphat…
Eukaryotic tRNAs(Pro): primary structure of the anticodon loop; presence of 5-carbamoylmethyluridine or inosine as the first nucleoside of the anticodon.
The modified nucleoside U*, located in the first position of the anticodon of yeast, chicken liver and bovine liver tRNA(Pro) (anticodon U*GG), has been determined by means of TLC, HPLC, ultraviolet spectrum and gas chromatography-mass spectrometry. The structure was established as 5-carbamoylmethyluridine (ncm5U). In addition, we report on the primary structures of the above-mentioned tRNAs as well as those which have the IGG anticodon. In yeast, the two tRNA(Pro) (anticodons U*GG and IGG) differ by eight nucleotides, whereas in chicken and in bovine liver, both anticodons are carried by the same 'body tRNA' with one posttranscriptional exception at position 32, where pseudouridine is asso…
Identification and structural characterization of O-beta-ribosyl-(1"----2')-adenosine-5"-phosphate in yeast methionine initiator tRNA.
We report in this paper on the complete structure determination of the modified nucleotide A*, now called Ar(p), that was previously identified in yeast methionine initiator tRNA as an isomeric form of O-ribosyl-adenosine bearing an additional phosphoryl-monoester group on its ribose2 moiety. By using the chemical procedure of periodate oxidation and subsequent beta-elimination with cyclohexylamine on mono- and dinucleotides containing Ar(p), we characterized the location of the phosphate group on the C-5" of the ribose2 moiety, and the linkage between the two riboses as a (1"----2')-glycosidic bond. Since the structural difference between phosphatase treated Ar(p) and authentic O-alpha-rib…