Isolation and characterization of presumed 3,5-diribosyluracil

A General Procedure for the Isolation of “Minor” Nucleosides from Ribonucleic Acid Hydrolysates*

“…Adenosine-R was heated at 100°i n 0.1 n hydrochloric acid for 2 hours. Chromatography of the reaction mixture in five solvent systems showed a " Five additional compounds not detected in the present work have been isolated from the hydrolysates of RNA of yeast and/or other tissues: Ar6,N6-dimethyladenine and 2-methyladenine (Littlefield and Dunn, 1958), 1,5-diribosyluracil (Lis and Lis, 1962), 7-methylguanine (Dunn, 1963), and A2-ribosylguanine (Hemmens, 1964;Shapiro and Gordon, 1964).…”

Conformation of pseudouridine and pseudouridine 5'-phosphate. Ultraviolet and nuclear magnetic resonance study

“…Very often it is present as a terminalpair in doublestranded regions at the beginning of a loop. Although the most tempting structure of 1,5-diribosyluracil as a component of RNA Lis, 1963,1964) or as an intermediate in enzymatic transformation of uridine to pseudouridine (Poliak and Arnstein, 1962;Lis and Lis, 1962) has been disproved by the synthesis of this diriboside (Dugaiczyk, 1965;Brown et al, 1965;Dugaiczyk and Eiler, 1966),* 12 the unique structure of pseudouridine has retained its potential for an active role in transfer RNA in the mechanism of protein biosynthesis.…”

Pseudouridylic Kinase Activity in Escherichia coli*

“…Heinrickson and Goldwasser (1964) have demonstrated the formation of i/'UMP from uracil and ribose-l-P04 in Tetrahymena pyriformis but this activity has not been demonstrated in any other organism or tissue. There have been reports of isolation of diribosyluridine derivatives which might serve as intermediates in the conversion of uridylic acid into their pseudouridine counterparts (Lis and Lis, 1962;Pollack and Arnstein, 1962), but their actual participation in such reactions has not been conclusively demonstrated. Robbin's kinetic data suggest intramolecular rearrangement; this could occur on the mononucleotide as well as on the polynucleotide level.…”