title: Selenium-Mediated Dehalogenation of Halogenated Nucleosides and its Relevance to the DNA Repair Pathway.
abstract: Halogenated nucleosides can be incorporated into the newly synthesized DNA of replicating cells and therefore are commonly used in the detection of proliferating cells in living tissues. Dehalogenation of these modified nucleosides is one of the key pathways involved in DNA repair mediated by the uracil-DNA glycosylase. Herein, we report the first example of a selenium-mediated dehalogenation of halogenated nucleosides. We also show that the mechanism for the debromination is remarkably different from that of deiodination and that the presence of a ribose or deoxyribose moiety in the nucleosides facilitates the deiodination. The results described herein should help in understanding the metabolism of halogenated nucleosides in DNA and RNA.
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012 (India).
authors.forename: Santanu
authors.initials: S
authors.lastname: Mondal
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012 (India).
authors.forename: Debasish
authors.initials: D
authors.lastname: Manna
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012 (India). mugesh@ipc.iisc.ernet.in.
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Mugesh
mesh_terms: D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair; D054879:Halogenation; D008968:Molecular Conformation; D009705:Nucleosides / Q000737:chemistry* / Q000378:metabolism; D012643:Selenium / Q000737:chemistry*; D055672:Static Electricity; D051981:Uracil-DNA Glycosidase / Q000378:metabolism
chemical_list: D009705:Nucleosides; D004247:DNA; D051981:Uracil-DNA Glycosidase; D012643:Selenium
keywords: DNA repair; dehalogenation; halogen bonds; nucleosides; selenium