The UV photoelectron spectra of adenine, 9-methyladenine, and 6-methylaminopurine contain highly resolved bands arising from the six highest occupied molecular orbitals. The spectra have been analyzed using UV absorption data, photoelectron data from previous studies of heterocyclic compounds, and results from both semi-empirical and ab initio molecular orbital calculations. The analysis indica...

The methylation of Escherichia coli B transfer RNA in vitro by HeLa mitochondrial and cytoplasmic extracts was examined. The following differences were found. (a) The cytoplasmic extract methylated E. coli B tRNA to a much greater extent than did the mitochondrial extract. (b) The two extracts methylated different sites on E. coli B tRNA, thereby generating different methylated oligonucleotide ...

The monofunctional platinum anticancer agent phenanthriplatin generates covalent adducts with the purine bases guanine and adenine. Preferential nucleotide binding was investigated by using a polymerase stop assay and linear DNA amplification with a 163-base pair DNA double helix. Similarly to cisplatin, phenanthriplatin forms the majority of adducts at guanosine residues, but significant diffe...

The human 3-methyladenine DNA glycosylase (AAG) recognizes and excises a broad range of purines damaged by alkylation and oxidative damage, including 3-methyladenine, 7-methylguanine, hypoxanthine (Hx), and 1,N(6)-ethenoadenine (epsilonA). The crystal structures of AAG bound to epsilonA have provided insights into the structural basis for substrate recognition, base excision, and exclusion of n...

The methylation of Escherichia coli B transfer RNA in vitro by HeLa mitochondrial and cytoplasmic extracts was examined. The following differences were found. (a) The cytoplasmic extract methylated E. coli B tRNA to a much greater extent than did the mitochondrial extract. (b) The two extracts methylated different sites on E. coli B tRNA, thereby generating different methylated oligonucleotide ...