Zebularine (1-(beta-D-ribofuranosyl)-1,2-dihydropyrimidin-2-one) was studied as both a 2 '-deoxyribosyl 5 '-triphosphate derivative and as a template incorporated into an oligonucleotide. Using a novel pyrosequencing assay, zebularine acted as cytosine analog and was incorporated into DNA with a template pairing profile most similar to cytosine, pairing with greatest efficiency opposite guanine...

The hierarchical self-assembly of various lipophilic guanosines exposing either a phenyl or ferrocenyl group in the C(8) position was investigated. In solution, all derivatives were found to self-assemble primarily into isolated guanine (G)-quartets. spite apparent similar bulkiness two substituents, most form disordered structures solid state, whereas specific 8-phenyl derivative self-assemble...

A synthetic DNA fragment was constructed to determine the effect of 5' and 3' neighbors of guanine runs on the binding of chemical carcinogens. Determinations were made on the relative intensity of reactivity between aflatoxin B1 or benzo(a)pyrene and methylnitrosourea or 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea with various guanine positions in an endlabeled DNA fragment of known sequence....

The Lesch-Nyhan syndrome has been characterized by an apparently complete deficiency in erythrocytes of an enzyme of purine metabolism, hypoxanthine-guanine phosphoribosyltransferase. Recent studies have suggested that low levels of this enzyme may be present in skin fibroblasts cultured from these patients. In the present study, we have confirmed the presence of hypoxanthine-guanine phosphorib...

The heavy metal ions-nucleobases interaction is an important research topic in environmental and biochemical analysis. The presence of the silver ion (Ag(+)) may influence the formation of oxidation intermediate and the electrocatalytic oxidation activity of guanine (G), since Ag(+) can interact with guanine at the binding sites which are involved in the electrocatalytic oxidation reaction of g...

Endogenous 5-methylcytosine ((Me)C) residues are found at all CG dinucleotides of the p53 tumor suppressor gene, including the mutational 'hotspots' for smoking induced lung cancer. (Me)C enhances the reactivity of its base paired guanine towards carcinogenic diolepoxide metabolites of polycyclic aromatic hydrocarbons (PAH) present in cigarette smoke. In the present study, the structural basis ...

The Lesch-Nyhan syndrome has been characterized by an apparently complete deficiency in erythrocytes of an enzyme of purine metabolism, hypoxanthine-guanine phosphoribosyltransferase. Recent studies have suggested that low levels of this enzyme may be present in skin fibroblasts cultured from these patients. In the present study, we have confirmed the presence of hypoxanthine-guanine phosphorib...

Highly transcribed guanine-run containing sequences, in Saccharomyces cerevisiae, become unstable when topoisomerase I (Top1) is disrupted. Topological changes, such as the formation of extended RNA:DNA hybrids or R-loops or non-canonical DNA structures including G-quadruplexes has been proposed as the major underlying cause of the transcription-linked genome instability. Here, we report that R...

Prebiotic molecules, fundamental building blocks for the origin of life, have been found in carbonaceous chondrites. The exogenous delivery these organic molecules onto Hadean Earth could sparked polymerization first RNA Darwinian ponds during wet-dry cycles. Here, we investigate formation and DNA nucleobases adenine, uracil, cytosine, guanine, thymine inside parent body planetesimals An up-to-...

background: aberrant methylation of cytosine-guanine dinucleotide islands leads to inactivation of tumor suppressor genes in breast cancer. tumor suppressor genes are unmethylated in normal tissue and often become hypermethylated during tumor formation, leading to gene silencing. we investigated the association between e-cadherin ( cdh1) and estrogen receptor-α (esrα) gene promoter methylation ...