Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The recently discovered human DNA polymerase lambda (DNA pol lambda) has been implicated in translesion DNA synthesis across abasic sites. One remarkable feature of this enzyme is its preference for Mn(2+) over Mg(2+) as the activating metal ion, but the molecular basis for this preference is not known. Here, we present a kinetic and thermodynamic analysis of the DNA polymerase reaction catalyzed by full length human DNA pol lambda, showing that Mn(2+) favors specifically the catalytic step of nucleotide incorporation. Besides acting as a poor coactivator for catalysis, Mg(2+) appeared to bind also to an allosteric site, resulting in the inhibition of the synthetic activity of DNA pol lambda and in an increased sensitivity to end product (pyrophosphate) inhibition. Comparison with the closely related enzyme human DNA pol beta, as well as with other DNA synthesising enzymes (mammalian DNA pol alpha and DNA pol delta, Escherichia coli DNA pol I, and HIV-1 reverse transcriptase) indicated that these features are unique to DNA pol lambda. A deletion mutant of DNA pol lambda, which contained the highly conserved catalytic core only representing the C-terminal half of the protein, showed biochemical properties comparable to the full length enzyme but clearly different from the close homologue DNA pol beta, highlighting the existence of important differences between DNA pol lambda and DNA pol beta, despite a high degree of sequence similarity.
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PMID:Human DNA polymerase lambda diverged in evolution from DNA polymerase beta toward specific Mn(++) dependence: a kinetic and thermodynamic study. 1280 3

We previously reported that a phenolic compound, curcumin (diferuloylmethane), was a selective inhibitor of DNA polymerase lambda (pol lambda) in vitro [Y. Mizushina, M. Hirota, C. Murakami, T. Ishidoh, S. Kamisuki, N. Shimazaki, M. Takemura, M. Perpelescu, M. Suzuki, H. Yoshida, F. Sugawara, O. Koiwai, K. Sakaguchi, Some anti-chronic inflammatory compounds are DNA polymerase lambda-specific inhibitors, Biochem. Pharmacol. 66 (2003) 1935-1944.]. We also found that monoacetylcurcumin ([1E,4Z,6E]-7-(4''-acetoxy-3''-methoxyphenyl)-5-hydroxy-1-(4'-hydroxy-3'-methoxyphenyl)hepta-1,4,6-trien-3-on), a chemically synthesized derivative of curcumin, was a stronger pol lambda inhibitor than curcumin, achieving 50% inhibition at a concentration of 3.9microM. Monoacetylcurcumin did not influence the activities of replicative pols such as alpha, delta, and epsilon, and showed no effect even on the activity of pol beta, the three-dimensional structure of which is thought to be highly similar to that of pol lambda. The compound-induced inhibition of pol lambda activity was non-competitive with respect to both the DNA template-primer and the dNTP substrate. Monoacetylcurcumin did not inhibit the activity of the C-terminal catalytic domain of pol lambda including the pol beta-like core, in which the BRCT motif was deleted. The compound did not influence the activities of prokaryotic pols or other mammalian DNA metabolizing enzymes such as calf primase of pol alpha, calf terminal deoxynucleotidyl transferase, human telomerase, human immunodeficiency virus type-1 reverse transcriptase, T7 RNA polymerase, T4 polynucleotide kinase, and bovine deoxyribonuclease I. Therefore, we concluded that monoacetylcurcumin is a selective inhibitor of pol lambda and could be used as a chromatographic ligand to purify pol lambda. We then made a monoacetylcurcumin-conjugated column with epoxy-activated Sepharose 6B. In the column, pol lambda of full length was selectively adsorbed and eluted.
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PMID:Monoacetylcurcumin: a new inhibitor of eukaryotic DNA polymerase lambda and a new ligand for inhibitor-affinity chromatography. 1623 65

Tetralols 1 and 2, dihydroisocoumarins 3-6, and chromone 7 are natural compounds isolated from cultures of fungi, and their structures were determined by spectroscopic analyses. Compounds 1 and 2 from Nodulisporium sp. are novel tetralols, 1,2,3,4-tetrahydro-5-methoxynaphthalene-1,4-diol (nodulisporol) and 3,4-dihydro-4-hydroxy-8-methoxynaphthalen-1(2H)-one (nodulisporone), respectively. All isolated compounds selectively inhibited the activity of human DNA polymerase lambda (pol lambda), and compound 5 (3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin) was the strongest inhibitor of pol lambda in the tested compounds with an IC(50) value of 49 microM. New tetralols (1 and 2) are the third and second strongest inhibitors of pol lambda, but did not influence the activities of mammalian pols alpha to kappa, and showed no effect even on the activities of plant pols alpha and beta, prokaryotic pols, and other DNA metabolic enzymes such as calf terminal deoxynucleotidyl transferase, human immunodeficiency virus type-1 (HIV-1) reverse transcriptase, human telomerase, T7 RNA polymerase, and bovine deoxyribonuclease I. The structure-activity relationships of isolated compounds such as novel tetralols, dihydroisocoumarins, and chromone are discussed.
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PMID:Nodulisporol and Nodulisporone, novel specific inhibitors of human DNA polymerase lambda from a fungus, Nodulisporium sp. 1736 59