Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty-eight base complementary oligonucleotides were synthesized with deoxyadenosine residues modified at the N6 position with 1-methylpyrene (MP) specifically positioned 3 bp apart in opposite DNA strands. Doubly modified constructs as well as non-modified and singly modified constructs were ligated into M13mp19 and an SV40-based shuttle vector pSVL-lac for transfection into Escherichia coli and large T-antigen-expressing monkey kidney epithelial cells respectively. Repair of MP adducts was analyzed by direct nucleotide sequencing after selection of clones containing the 28mer construct. In E. coli, double MP adducts induced base substitutions at positions mainly adjacent to modified adenines, while single MP adducts were not mutagenic. Single base insertions were also induced proximal to modified adenines. The frequency of mutation induced by double MP adducts in E. coli was approximately 4% (eight mutations out of 196 analyzed). In monkey kidney cells, double MP adducts induced one and three base deletions and single base insertions. Base substitution was observed in constructs containing non-modified and singly modified adenine residues, indicative of a significant spontaneous mutation rate. The frequency of mutation induced by double MP adducts in monkey kidney cells was approximately 9% (six mutations out of 66 clones analyzed). Modification of adenine residues by MP caused termination of DNA replication by E. coli DNA polymerase I (Klenow fragment) in vitro at the position opposite the MP adduct and at the preceding base. The repair of closely spaced polycyclic aromatic hydrocarbon adducts in opposite DNA strands is discussed as it relates to mutagenesis and carcinogenesis in mammalian cells.
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PMID:Mutation in Escherichia coli and mammalian cells induced by closely spaced 1-methylpyrene-deoxyadenosine adducts in opposite DNA strands. 847 28

ATP gamma-amides containing in gamma-N-position 1-methylpyrene, 9-methylanthracene, 10-chloro-9-methylanthracene, and 3-methylperylene residues were synthesized and characterized. These compounds were used as sensitizers of site-specific photomodification of the reconstituted elongating complex of the mammalian DNA polymerase beta. The photomodification was carried out with the use of photoaffine reagents, which were synthesized in situ by the 5'-(32)P-labeled primers extension with photoactive analogues of dCTP containing in the exo-N-position of cytosine various perfluoroarylazide groups. The effect of structures of the sensitizers and photoactive reagents on the efficiency and selectivity of photolinking of primers to the enzyme and template, as well as formation of a number of other photomodification products was studied. It was shown that the sensitizers containing 10-chloro-9-methylanthracene and 3-methylperylene residues allow preparation of photolinks in such irradiation conditions when photomodification in their absence is not essentially observed.
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PMID:[Reagents for modification of protein-nucleic complexes. III. Site-specific photomodification of elongation complex of DNA polymerase beta with arylazide derivatives of primers sensitized with fluorescent ATP gamma-amide]. 1164 12