Ea. Atencia et al., Several dinucleoside polyphosphates are acceptor substrates in the T4 RNA ligase catalyzed reaction, EUR J BIOCH, 267(6), 2000, pp. 1707-1714
Several dinucleoside polyphosphates accept cytidine-3',5'-bisphosphate from
the adenylylated donor 5'-adenylylated cytidine 5',3'-bisphosphate in the
T4 RNA ligase catalyzed reaction. The 5'-adenylylated cytidine 5',3'-bispho
sphate synthesized in a first step, from ATP and cytidine-3',5'-bisphosphat
e, is used as a substrate to transfer the cytidine-3',5'-bisphosphate resid
ue to the 3'-OH group(s) of diguanosine tetraphosphate (Gp(4)G) giving rise
to Gp(4)GpCp and pCpGp(4)GpCp in a ratio of approximate to 10 : 1, respect
ively. The synthesized Gp(4)GpCp was characterized by treatment with snake
venom phosphodiesterase and alkaline phosphatase and analysis (chromatograp
hic position and UV spectra) of the reaction products by HPLC. The apparent
K-m values measured for Gp(4)G and 5'-adenylylated cytidine 5',3'-bisphosp
hate in this reaction were approximate to 4 mm and 0.4 mm, respectively. In
the presence of 0.5 mm ATP and 0.5 mm cytidine-3',5'-bisphosphate, the rel
ative efficiencies of the following nucleoside(5')oligophospho(5')nucleosid
es as acceptors of cytidine-3',5'-bisphosphate from 5'-adenylylated cytidin
e 5',3'-bisphosphate are indicated in parentheses: Gp(4)G (100); Gp(5)G (10
1); Ap(4)G (47); Ap(4)A (39). Gp(2)G, Gp(3)G and Xp(4)X were not substrates
of the reaction. Dinucleotides containing two guanines and at least four i
nner phosphates were the preferred acceptors of cytidine-3',5'-bisphosphate
at their 3'-OH group(s).