Nucleic Acids Research, Vol 24, Issue 17 3364-3369, Copyright © 1996 by Oxford University Press
T Yamaguchi and M Saneyoshi
In order to develop a photoaffinity labeling reagent for DNA polymerases,
including retroviral reverse transcriptase (RT), we utilized
2',3'-dideoxy-E-5-[4-(3-trifluoromethyl-3H-diazirin-3-yl) styryl]UTP
(TDSddUTP) as a substrate dTTP analog. Photoaffinity labeling experiments
with human immunodeficiency virus type-1 (HIV-1) RT using a radioactive
labeling reagent ([gamma-32P]TDSddUTP) and poly(A).oligo(dT) as the
template/primer yielded different results depending on the concentration of
Mg2+. In the presence of 0.025 mM Mg2+, photoaffinity labeling showed that
TDSddUTP bound selectively to the dTTP binding site in the 66 kDa subunit
of the p66/p51 heterodimeric enzyme protein when irradiated by near-UV
light (365 nm). In the presence of 4 mM Mg2+ or 0.05 mM Mn2+, TDSddUTP was
incorporated into the 3'-end of the primer strand due to RT activity and
the resulting photolabile primer bound to the 66 kDa subunit of HIV-1 RT on
photoirradiation. These results suggest that TDSddUTP could be a useful
tool for studying the substrate binding site(s) of DNA polymerases,
including HIV-1 RT, which show affinity for this compound.
ARTICLES
A photolabile 2',3'-dideoxyuridylate analog bearing an aryl(trifluoromethyl)diazirine moiety: photoaffinity labeling of HIV-1 reverse transcriptase
Department of Biological Sciences, Teikyo University of Science and Technology, Yamanashi, Japan.
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