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)

Procedures were established for the isolation and partial purification of DNA polymerase, RNA polymerase and poly(A) polymerase activities from the cytoplasm and nuclei of NIH-Swiss mouse embryos. Based on the elution pattern of these enzyme activities from DEAE-cellulose and phosphocellulose columns in Tris-HCl buffer, pH 8.0, the apparent basicities of the enzymes can be arranged as follows: cytoplasmic(C) poly(A) polymerase greater than (C)DNA polymerase beta greater than (C)DNA polymerase alpha and nuclear(N) poly(A) polymerase greater than (N)DNA polymerase greater than (N)RNA polymerase I greater than (N)RNA polymerase II. Twenty rifamycins, including rifamycin B, rifamycin S, rifamycin SV, and rifamycin SV derivatives, were examined for their ability to inhibit the above mentioned nucleic acid polymerizing enzymes and Simian sarcoma virus type I (SSV-1) reverse transcriptase. Rifamycin SV 3'-formyldiphenylhydrazone, rifamycin SV 3'-formyl-n-octyloxime (AF/013) and rifamycin SV 3'-formyldiphenylmethyloxime (AF/05) inhibited all the tested enzyme activities. Rifamycin SV 3'-formylpropylphenyloxime (AF/015) inhibited cellular nucleic acid polymerase activities but not SSV-1 DNA polymerase activity. Rifamycin SV 3'-formyldinitrophenylhydrazone (AF/DNFL) strongly inhibited reverse transcriptase activity but did not inhibit cellular DNA polymerase activities. AF/DNFI slightly inhibited RNA and poly(A) polymerase activities. Rifamycin SV 3'-formyldipropylhydrazone (AF/DPI) and 2,6-dimethyl-4-N-benzyldemethyl-rifampicin (AF/ABDMP) slightly inhibited reverse transcriptase activity but did not inhibit cellular nucleic acid polymerase activities. Active rifamycin derivatives inhibited enzyme reactions by interacting with the enzyme proteins. Nascent polynucleotide chain elongation continued although at a reduced rate in the presence of inhibitor. The addition of increasing concentrations of nonionic detergent (Triton X-100) to rifamycin-inhibited enzyme reactions fully restored enzyme activities. The presence of highly lipophilic 3'-side chains on active rifamycins and the reversibility of enzyme inhibition by Triton X-100 suggest that the tested nucleic acid polymerizing enzymes may have hydrophobic regions with which inhibitory rifamycins interact.
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PMID:Interaction of rifamycins with mammalian nucleic acid polymerizing enzymes. 6 93

Antibodies directed against reverse transcriptases (RT) of the mammalian retroviruses SSV and RD114 recognize specifically on Western Blots yeast cytoplasmic soluble proteins of 31 and 45 kDa respectively and inhibit RT activity in this fraction. Anti RLV RTIgG recognizes a protein of 40-43 kDa in the particulate (VLP) fraction and inhibits RT activity in it. No inhibition of RT activity was seen with normal serum anti AMV RTIgG or antisera against yeast DNA polymerase I and DNA polymerase III. These yeast RTs display RNase H activity and are not inhibited by aphidicolin. They prefer Mn+2 as cofactor over Mg+2, display an optimum temperature of 25-30 degrees C and are expressed in a diploid as well as 2 haploid strains and are thus distinct from yeast Ty encoded RTs.
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PMID:Some yeast proteins are recognized by antibodies to reverse transcriptases from several mammalian retroviruses and display reverse transcriptase activity. 171 50

Enzymological properties of the RNA-directed DNA polymerase associated with the Suncus murinus mammary tumor virus (Sm-MTV) was investigated and its antigenic relatedness to other retroviral DNA polymerases was examined. The enzyme exhibited higher activity in the presence of Mg2+ than in the presence of Mn2+ with endogenous RNA as well as with almost all of the synthetic template X primers tested. Mg2+ was also effective with poly(2'-O-methylcytidylate) X oligodeoxyguanylate which was known to be specific for Mn2+. To examine the immunological relatedness of this enzyme with other retroviral DNA polymerases, remaining Sm-MTV DNA polymerase activity was measured after treatment of this enzyme with various antisera prepared against each of the reverse transcriptases of Mason-Pfizer monkey virus (MPMV), murine mammary tumor virus (MuMTV), simian sarcoma virus-simian sarcoma associated virus (SSV/SSAV), and Rauscher murine leukemia virus (RLV). No inhibition of the Sm-MTV enzyme activity was observed when treated with the latter three antisera with which the DNA polymerase activities of the corresponding retroviruses were fully inhibited. Only the antiserum against MPMV-enzyme, however, was found to slightly inhibit the Sm-MTV enzyme activity. These results indicate that Sm-MTV DNA polymerase has similar enzymological properties to those of MPMV and MuMTV and shares some common antigenic determinant group(s) with MPMV DNA polymerase.
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PMID:Biochemical and immunological characterization of Suncus murinus mammary tumor virus DNA polymerase. 241 16

Chronic myelogenous leukemia (CML) is a stem cell disease which, on a clinical level, progresses from the release from growth control of normally differentiated cells (a preleukemic state) to an acute leukemia. On a molecular level, the evolution of CML to acute leukemia is a multistep process. We propose that an early step, at the stem cell level, is acquisition of the ability for gene movement, which allows subsequent submicroscopic and chromosomal rearrangements that cause changes in the growth characteristics and regulation of the stem cell. A specific platelet DNA polymerase (PDP - reverse transcriptase) may play a role in gene movement. The characteristic reciprocal translocation of chromosomes #9 and #22, causing the activation of the c-abl oncogene, appears to be responsible for the uncontrolled cellular growth. Yet, other growth factors (e.g., platelet derived growth factor) and activated oncogenes (e.g., c-sis) must be responsible for the stimulation, progression, and variability seen during the course of the disease. Because CML is a progressive disease with clinically definable stages, CML appears to be a model system for the study of the molecular basis of the progression of preleukemia to leukemia specifically, and preneoplasia to aggressive neoplasia in general.
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PMID:Implications of retroviral and oncogene activity in chronic myelogenous leukemia. 243 4

A modified assay of nick-translation of nuclei has been developed to study the chromatin structure of human beta-like globin genes in nuclei of K 562 cell line. Nuclei were gently digested with DNase I and nick-translated with E. coli DNA polymerase I in the presence of 32P-triphosphate nucleotides. The total DNA from the labelled nuclei was used as probes to hybridize restricted fragments of beta-like globin genes which have been immobilized on Diazobenzyloxymethyl (DBM) paper. Using this approach we have observed that in K 562 nuclei all beta-like globin genes, including epsilon, gamma, delta, and beta-globin genes and human 18 S ribosomal genes are preferentially labelled in comparison to alpha-lactalbumin and c-sis genes which do not express in K 562 cells, but the total DNA from nick-translated nuclei of a nonerythroid cell line hybridized none of those genes except for 18 S ribosomal gene. This assay is a simple and fast method for surveying chromatin structure of any individual DNA sequence in nuclei once the corresponding clone is available.
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PMID:A study of the chromatin structure of human beta-like hemoglobin genes in K562 cell line with a modified assay of nick-translation of nuclei. 262 96