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-ribosyl-(1"----2')-adenosine from poly(ADP-Ribose) was previously assigned to an isomeric difference in the ribose2-ribose1 linkage, the (1"----2')-glycosidic bond of Ar(p) was deduced to have a beta-spatial configuration. Thus, final chemical structure for Ar(p) at the position 64 in yeast initiator tRNA(Met) has been established as O-beta-ribosyl-(1"----2')-adenosine-5"-phosphate. This nucleotide is linked by a 3',5'-phosphodiester bond to G at the position 65.
Keith
G
G
Institut de Biologie Moléculaire et Cellulaire, CNRS, Strasbourg, France.
Glasser
A L
AL
Desgrès
J
J
Kuo
K C
KC
Gehrke
C W
CW
D000249:Adenosine Monophosphate / Q000031:analogs & derivatives* / Q000032:analysis / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D012358:RNA, Transfer, Met / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D007202:Indicators and Reagents; D012358:RNA, Transfer, Met; C066273:O-beta-ribosyl(1''--2')adenosine-5''-phosphate; D000249:Adenosine Monophosphate