Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.5.1.2 (DNA ligase)
 2,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-Methylpurine-DNA glycosylase (MPG), a ubiquitous DNA repair enzyme, removes N-alkylpurines and other purine lesions induced in DNA by simple alkylating carcinogens. A mouse MPG cDNA clone was isolated from a lambda recombinant phage library of BALB/c mouse lung cell and characterized. Using the mouse MPG cDNA as a probe, the complete mouse MPG gene was isolated in two overlapping lambda recombinant genomic clones. The 6-kb gene has four exons containing 1,002 bp of coding sequence. The transcription start site was identified in the genomic sequence by primer extension of MPG mRNA from a mouse lung fibroblast cell line. The location of this transcription start site was confirmed by in vitro transcription with the promoter-containing plasmid template. Promoter function of the sequence 5' upstream of the transcription initiation site was shown by transient expression of the firefly luciferase reporter gene under the control of this sequence in transfected human and mouse cells. The mouse MPG promoter contains no TATA box, but has a CAAT element and is G.C-rich with putative AP2 elements and SP1-complementary sequences.
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PMID:Structural organization of the mouse DNA repair gene, N-methylpurine-DNA glycosylase. 783 91

ATP-dependent enzymes were investigated as to the stringency of their ATP requirement. For all the enzymes examined except firefly luciferase (including hexokinase, polynucleotide kinase, T4 DNA ligase, and T4 RNA ligase) ATP could be replaced with dATP, contradicting previous data. Considering the replaceable nucleotides, not only kinases (low stringency as to ATP-requirement) but also other enzymes (moderate stringency) were typed as phosphate-directed ATP recognition. Through this study, an exact view of ATP-requiring enzymes which have a profound influence on the concentration in a cell of ATP, a metabolic and regulative key substance, was obtained, and a technically useful, fluorescent ATP-substitute (2AP-TP) was introduced.
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PMID:Unexpectedly general replaceability of ATP in ATP-requiring enzymes. 927 90

Compounds of the mevalonate pathway containing a terminal di- or triphosphate (mev-PP or mev-PPP) were tested as substrates of several enzyme ligases (T4 RNA ligase, T4 DNA ligase, firefly luciferase and other ligases) for the synthesis of ATP derivatives of the mev-pppA or mev-ppppA type. T4 RNA ligase, in the presence of ATP and the substrates: geranyl, farnesyl or isopentenyl triphosphates, and geranyl, farnesyl, dimethylallyl or isopentenyl diphosphates, all at 0.3 mM concentration, catalyzed the synthesis of the corresponding ATP derivatives at a relative rate of activity of: 7.6+/-1.4 mU/mg or 100%; 39%; 42%; 24%; 18%; 12% and 6%, respectively. Inhibition (%) of the synthesis by excess of substrate (0.8 mM vs. 0.3 mM) was observed with farnesyl diphosphate (99%); farnesyl triphosphate (96%) and geranyl triphosphate (32%). V(max), K(m), K(cat) and K(cat)/K(m) values were also determined. The K(cat)/K(m) values calculated were for: farnesyl triphosphate, 166; geranyl triphosphate, 52.2; farnesyl diphosphate, 12.1; geranyl diphosphate, 8.6; isopentenyl triphosphate, 6.7; dimethylallyl diphosphate, 3.1 and isopentenyl diphosphate, 0.9. Similar results were obtained with T4 DNA ligase. The above-mentioned compounds were also substrates of firefly luciferase synthesizing the mev-pppA or mev-ppppA derivatives. In our hands, neither the acyl- or acetyl-CoA synthetases nor the ubiquiting activating enzyme (E1) catalyzed the synthesis of ATP derivatives of these compounds. The results here presented could be related with the mechanism of action of bisphosphonates on osteoclasts or tumor cells.
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PMID:Synthesis of ATP derivatives of compounds of the mevalonate pathway (isopentenyl di- and triphosphate; geranyl di- and triphosphate, farnesyl di- and triphosphate, and dimethylallyl diphosphate) catalyzed by T4 RNA ligase, T4 DNA ligase and other ligases Potential relationship with the effect of bisphosphonates on osteoclasts. 1941