Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.25.1 (deoxyribonuclease)
 1,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The two high-molecular-weight DNA polymerases from Euglena gracilis, pol A (mol. wt. 190 000) and pol B (mol. wt. 240 000), were differentiated on the basis of associated enzymic activities and primer-template utilization. Neither enzyme had endodeoxyribonuclease activity, but pol B, like pol B of yeast and the corresponding enzyme from Tetrahymena pyriformis, exhibited at least one other nuclease activity directed against denatured DNA and the RNA of an RNA-DNA hybrid. These nuclease functions preferred an alkaline pH and Mg2+. Pol B also exhibited nucleoside diphosphokinase activity. Both enzymes were active with 'activated' DNA and poly[d(A-T)] as primer-templates and were sensitive, especially pol B, to inhibition by excess of native or heat-denatured DNA. Pol B also utilized oligo[d(T)] and poly(A) templates under certain conditions, whereas pol A exhibited only slight activity with poly[d(A)]. (U)6 was not used as a primer by either enzyme.
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PMID:Deoxyribonucleic acid polymerases of Euglena gracilis. Primer-template utilization of and enzyme activities associated with the two deoxyribonucleic acid polymerases of high molecular weight. 0 62

Preparations of purified Rauscher murine leukemia virus were found to contain an endodeoxyribonuclease after disruption of the virus with nonionic detergents. The enzyme makes single-strand breaks in linear or covalently closed circular phage double-stranded DNA molecules. The enzyme was partially purified by ion-exchange chromatography on DEAE- and carboxymethyl-Sepharose columns followed by electrophoresis in DNA-containing polyacrylamide gels. The enzyme was separated from reverse transcriptase (p80pol), and the final endonuclease preparation contained no detectable reverse transcriptase activity. The DEAE-Sepharose column-purified endonuclease activity contained a polypeptide of about 40,000 Mr that we term p40. Peptide mapping experiments demonstrated that p40 shares methionine-labeled tryptic peptides with Pr200gag-pol and Pr135pol. Six major methionine-labeled tryptic peptides derived from p40 were found in Pr200gag-pol, but only five of these were detected in Pr135pol. The four core proteins (p30, p15, pp12, and p10) and p80pol plus p40 account for most, but not all, of the peptide sequences of Pr200gag-pol. The endonuclease-associated p40 is similar in size and precursor origin to the avian retrovirus-coded endonuclease (p32). In view of these similarities to the avian p32 endonuclease and its association with partially purified Rauscher murine leukemia virus-associated endonuclease preparations, we propose that p40 is the Rauscher murine leukemia virus-coded endonuclease.
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PMID:Endodeoxyribonuclease activity associated with Rauscher murine leukemia virus. 626 Sep 82

Enzymes that release 5'-deoxyribose-5-phosphate (dRP) residues from preincised apurinic/apyrimidinic (AP) DNA have been collectively termed DNA deoxyribophosphodiesterases (dRPases), but they fall into two distinct categories: the hydrolytic dRPases and AP lyases. In order to resolve a number of conflicting reports in the dRPase literature, we examined two putative hydrolytic dRPases (Escherichia coli exonuclease I (exo I) and RecJ) and four AP lyases (E. coli 2, 6-dihydroxy-5N-formamidopyrimidine (Fapy) DNA glycosylase (Fpg) and endonuclease III (endo III), bacteriophage T4 endonuclease V (endo V), and rat polymerase beta (beta-pol)) for their abilities to (i) excise dRP from preincised AP DNA and (ii) incise AP DNA. Although exo I and RecJ exhibited robust 3' to 5' and 5' to 3' exonucleolytic activities, respectively, on appropriate substrates, they failed to demonstrate detectable dRPase activity. All four AP lyases possessed both dRPase and traditional AP lyase activities, albeit to varying degrees. Moreover, as best illustrated with Fpg, AP lyase enzymes could be trapped on both preincised and unincised AP DNA using NaBH(4) as the reducing agent. These results further support the assertion that the catalytic mechanism of the AP lyases, the beta-elimination reaction, does proceed through an imine enzyme-DNA intermediate and that the active site residues responsible for dRP release must contain primary amines. Further, these data indicate a biological significance for the beta-elimination reaction of DNA glycosylase/AP lyases in that they, in concert with hydrolytic AP endonucleases, can create appropriate gapped substrates for short patch base excision repair (BER) synthesis to occur efficiently.
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PMID:AP lyases and dRPases: commonality of mechanism. 1067 82

The glycolipid galactosyldiacylglycerol (GDG), containing C16:0 and C18:1 fatty acids, was isolated from the sea alga Petalonia bingbamiae as a potent inhibitor of the activities of mammalian DNA polymerase alpha (pol. alpha). GDG, however, had no effect on pol. alpha from a fish or a higher plant. The inhibition of pol. alpha by GDG was dose-dependent with an IC50 value of 54 microM. The compound did not influence the activities of other replicative DNA polymerases such as mammalian pol. delta, or repair-related enzymes such as mammalian pol. beta. GDG also did not influence the activities of prokaryotic DNA polymerases such as the Klenow fragment of DNA polymerase I, T4 DNA polymerase, Taq DNA polymerase, DNA polymerases from the higher plant, cauliflower, or DNA metabolic enzymes such as calf thymus terminal deoxynucleotidyl transferase, human immunodeficiency virus type 1 reverse transcriptase and deoxyribonuclease 1. Kinetic analysis of the compound showed that pol. alpha was non-competitively inhibited with respect to both the DNA template and the nucleotide substrate. In this study, we demonstrated the structure-function relationship in the selective inhibition of pol. alpha by the glycolipid group.
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PMID:Galactosyldiacylglycerol, a mammalian DNA polymerase alpha-specific inhibitor from a sea alga, Petalonia bingbamiae. 1155 81

The cytosine base in DNA undergoes hydrolytic deamination at a considerable rate when UV radiation induces formation of a cyclobutane pyrimidine dimer (CPD) with an adjacent pyrimidine base. We have synthesized a phosphoramidite building block of a cis-syn cyclobutane thymine-uracil dimer (T[]U), which is the deaminated form of the CPD at a TC site, and incorporated it into oligodeoxyribonucleotides. The previously reported method for synthesis of the thymine dimer (T[]T) was applied, using partially protected thymidylyl-(3'-5')-2'-deoxyuridine as the starting material, and after triplet- sensitized irradiation, the configuration of the base moiety in the major product was determined by NMR spectroscopy. Presence of the cis-syn cyclobutane dimer in the obtained oligonucleotides was confirmed by UV photoreversal and reaction with T4 endonuclease V. Using a 30mer containing T[]U, translesion synthesis by human DNA polymerase eta was analyzed. There was no difference in the results between the templates containing T[]T and T[]U and pol eta bypassed both lesions with the same efficiency, incorporating two adenylates. This enzyme showed fidelity to base pair formation, but this replication causes a C-->T transition because the original sequence is TC.
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PMID:Chemical synthesis and translesion replication of a cis-syn cyclobutane thymine-uracil dimer. 1502 Jul 10