Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enzymes of DNA synthesis, thymidine kinase (ATP-thymidine-5'-phospho-transferase, EC 2.7.1.21), DNA polymerase (EC 2.7.7.7) and nuclease activities were investigated in isolated purified nuclei of swine aorta. Thymidine kinase which is detectable in these nuclei can be stimulated by the addition of phospholipase C. DNA polymerase activity of isolated nuclei is strongly dependent on addition of an exogenous template; the preferred template is activated DNA. The activity in the absence of an added template is very low except when labelled dCTP is used as the precursor. This incorporation of labelled dCTP does not require the addition of the other three triphosphates, and under these conditions, dCTP seems to be incorporated into what may be a homopolymer. As with other tissues, solubilized preparations of aortic nuclei have two DNA polymerase activities which also prefer activated DNA template. There is no detectable endonuclease in aortic nuclei.
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PMID:Enzymes of DNA synthesis in isolated nuclei of swin aorta. 94 21

The herpes simplex virus (HSV) type 1 dUTPase gene was inactivated by insertion of HindIII oligonucleotide linker sequences into the KpnI site within the coding region of the cloned gene. The mutated gene was introduced into wild type herpes simplex virus by marker rescue and the recombinants were identified by the acquisition of a HindIII site within genome map coordinates 0.69 to 0.70 and the failure to induce virus-specific dUTPase activity. A spontaneous dUTPase deficient mutant, which had an identical restriction endonuclease DNA pattern to wild type virus, was also isolated from this transfection experiment. Both types of dUTPase-negative mutants failed to induce a virus-specific 39,000 mol wt polypeptide. Cells infected with the insertional mutant contained instead a novel polypeptide about 40,000 mol wt. No abnormal virus specific polypeptide was detected in cells infected with the spontaneous mutant. We conclude that the 39,000 mol wt polypeptide induced by wild type HSV-1 is the virus-coded dUTPase. Since both types of mutants grew well in exponentially growing and serum-starved tissue culture cells in the absence of wild type helper virus, the dUTPase is not required for virus replication under these conditions. Thymidine kinase deficient, dUTPase deficient double mutants were constructed by recombination of a thymidine kinase insertional mutation into dUTPase deficient virus. These mutants also grew as well as wild type virus both in normal tissue culture cells and cells lacking the cellular thymidine kinase.
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PMID:Isolation and characterisation of herpes simplex virus type 1 mutants which fail to induce dUTPase activity. 300 29

We investigated the effect of pifithrin-alpha (PFTalpha), a chemical inhibitor of p53, on DNA double-strand break (DSB) repair in mammalian chromosomes. Thymidine kinase-deficient mouse fibroblasts were stably transfected with DNA substrates containing one or two recognition sites for yeast endonuclease I-SceI embedded within a herpes simplex virus thymidine kinase gene. Genomic DSBs were induced by introducing an I-SceI expression plasmid into cells in the presence or absence of 20 microM PFTalpha. From cells containing the DNA substrate with a single I-SceI site we recovered low-fidelity nonhomologous end-joining (NHEJ) events in which one or more nucleotides were deleted or inserted at the DSB. From cells containing the substrate with two I-SceI sites we recovered high-fidelity DNA end-joining (precise ligation (PL)) events. We found that treatment of cells with PFTalpha caused a 5-10-fold decrease in recovery of PL but decreased recovery of NHEJ by less than two-fold. Deletion sizes associated with NHEJ were unaffected by treatment with PFTalpha. Our work suggests the possibility that p53 facilitates high-fidelity DSB repair while playing little or no role in mutagenic NHEJ.
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PMID:Suppression of high-fidelity double-strand break repair in mammalian chromosomes by pifithrin-alpha, a chemical inhibitor of p53. 1250 64