3',5'-UpU TEA (3',5'-Uridylyluridine TEA) is a 3',5'-linked uridylyluridine dinucleotide. 3',5'-UpU TEA undergoes cyclization/cleavage reactions to form uridine and uridine 2',3'-cyclic phosphate, and can also isomerize into 2',5'-UpU. Under the consecutive acid-base bifunctional catalysis of imidazole buffer, 3',5'-UpU TEA undergoes cyclization/cleavage reactions via a phosphorane intermediate [1].
In Vitro, 3',5'-UpU (3.2 mM; 80°C) TEA undergoes cell-free cyclization/cleavage that is catalyzed 103-fold by a combination of 1 mM ZnCl2 and 10 mM imidazole at pH 7.00 and 80°C, with no acceleration of competing isomerization to 2',5'-UpU[1].
References:
[1]. Breslow R, et al. On the mechanism of action of ribonucleases: dinucleotide cleavage catalyzed by imidazole and Zn2+. Proceedings of the National Academy of Sciences of the United States of America. 1989 Mar;86(6):1746-50.
In Vitro, 3',5'-UpU (3.2 mM; 80°C) TEA undergoes cell-free cyclization/cleavage that is catalyzed 103-fold by a combination of 1 mM ZnCl2 and 10 mM imidazole at pH 7.00 and 80°C, with no acceleration of competing isomerization to 2',5'-UpU[1].
References:
[1]. Breslow R, et al. On the mechanism of action of ribonucleases: dinucleotide cleavage catalyzed by imidazole and Zn2+. Proceedings of the National Academy of Sciences of the United States of America. 1989 Mar;86(6):1746-50.
















