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

N(6)-furfuryladenine (kinetin, K) was shown to have cytokinin activity and antiageing effects. It also appears to protect DNA against oxidative damage mediated by the Fenton reaction. Kinetin was identified as a natural component of DNA in plant extract, calf thymus DNA, fresh DNA preparations from human cell culture, as well as in human urine. A proposed mechanism of kinetin synthesis includes furfural, the oxidative damage product of a 2-deoxyribose moiety of DNA, which reacts with an adenine residue to form N(6)-furfuryladenine at DNA level. The identification of kinetin in plant cell extracts, as well as human urine, suggests its excision from DNA by repair mechanisms. Since such a bulky modification as kinetin induces conformational changes of DNA, this could lead to mutations. Therefore, it was interesting to analyze an effect of kinetin on coding properties of DNA. Chemically synthesized oligodeoxynucleotide (20-mer) containing kinetin AAAACTGCCGTCCTGAKGAT was used as a primer. It was elongated in a polymerase chain reaction (PCR) on a template plasmid pEW1 harboring a 210-bp fragment of DNA derived from the 5' end of HIV mRNA. The PCR product of that length containing kinetin in position 17 from the 5' end was isolated and sequenced. Interestingly, DNA polymerase correctly incorporates thymine opposite of kinetin (an adenine derivative) on the complementary strand, but the misincorporations occur in a vicinity of the modified base.
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PMID:"Action-at-a distance" of a new DNA oxidative damage product 6-furfuryl-adenine (kinetin) on template properties of modified DNA. 1259 10

A binary system of reagents was used for photosensitized labeling of proteins of bovine testis nuclear extract. A dUTP analog containing 4-azido-2,5-difluoro-3-chloropyridyl group (FAP-dUTP) was used for the first time as a component of the binary system, and a dUTP analog containing the pyrenyl group (Pyr-dUTP) was used as a photosensitizer. Photoaffinity labeling of proteins of nuclear extract was performed using the radioactively labeled DNA duplex with the photoreactive FAP group at the 3;-end of elongating DNA strand and analog of the deoxyribose phosphate residue (3-hydroxy-2-hydroxymethyltetrahydrofuran (F) 5;-phosphate) at the 5;-end of the nick. Such structure is formed by the action of nuclear extract enzymes from the initial DNA duplex containing a synthetic apurine/apyrimidine site and is a photoreactive analog of a long-patch base excision repair intermediate. UV-irradiation modified a limited number of proteins of the nuclear extract. As shown using specific antibodies, the new binary system of photoreagents increases the efficiency of DNA polymerase beta labeling.
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PMID:A new binary system for photosensitized labeling of DNA polymerases in nuclear extract. 1276 32

A new base-substituted analogue of dCTP, exo-N-{2-[N-(4-azido-2,5-difluoro-3-chloropyridine-6-yl)-3-aminopropionyl]aminoethyl}-2'-deoxycytidine-5'-triphosphate (FAP-dCTP) has been synthesized and characterized. FAP-dCTP is an efficient substrate of mammalian DNA polymerase beta in the reaction of primer elongation displaying substrate properties as an analogue of dCTP and dTTP. FAP-dCTP was used for the photoaffinity modification of mammalian DNA polymerase beta. Two approaches to photoaffinity labeling were utilized. In one approach, photoreactive FAP-dCTP was first incorporated into radiolabeled primer-template, and photoreactive DNA was UV-irradiated in the presence of DNA polymerase beta, which resulted in the polymerase labeling by photoreactive primer. In an alternate approach, FAP-dCTP was first UV-cross-linked to the enzyme; subsequently, radiolabeled primer-template was added, and the enzyme-linked FAP-dCTP was incorporated into the 3'-end of radioactive primer. This "catalytic" modification pathway was shown to be less specific in recognition of FAP-dCTP as an analogue of dCTP than dTTP. FAP-dCTP was used as substrate of endogenous DNA polymerases of HeLa cell extract to synthesize photoreactive DNAs for photoaffinity modification of cell proteins. UV irradiation results in modification of DNA binding proteins of cell extract. The level of photoaffinity labeling of protein targets in the cell extract was strongly dependent on the efficiency of synthesis of photoreactive DNA.
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PMID:A new highly efficient photoreactive analogue of dCTP. Synthesis, characterization, and application in photoaffinity modification of DNA binding proteins. 1565 94