Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The restriction fragment Hind-K represents 4.2% of the genome of Simian virus 40 (SV40) and is located near the middle of the late region. Its nucleotide sequence is reported here. It was mainly established by analysis of transcription products, synthesized by means of Escherichia coli RNA polymerase and nucleoside triphosphates, one of which was (alpha-32P)-labeled. Strand assignment was possible by hybridization of asymmetric, labeled transcripts of total SV40 DNA to filter-bound Hind-K fragment. Further information and unambiguous confirmation of the sequence was obtained by the use of direct DNA-sequencing methods. For this purpose the fragment was labeled at the 5' ends by means of polynucleotide kinase and [gamma-32P]ATP and redigested with a suitable restriction enzyme. The separated products were then either partially digested with snake venom diesterase for analysis by the 'wandering spot' method or partially degraded with the base-specific reagents dimethylsulphate or hydrazine for direct sequence analysis on gel. The Hind-K sequence is 219 base pairs long. The message strand is particularly rich in adenosine (39%) and purines. The nucleotide sequence cna unambiguously be translated into an amino acid sequence and the N-terminal codon of the viral protein VP1 gene could be identified. The amino-terminal part of VP1 is rich in proline and lysine. The nucleotide sequence of Hind-K codes also for the carboxyl-terminal part of the viral protein VP2 and VP3 genes, which partly overlap the VP1 gene.
...
PMID:Nucleotide sequence of the simian virus 40 Hind-K restriction fragment. 20 17

Some properties of in vitro transcription by isolated Xenopus oocyte nucleoli were described. When incubated with labeled RNA precursors, Xenopus oocyte nucleoli exhibited prolonged incorporation of radioactivity into RNA. The synthetic activity was exclusively due to type I RNA polymerase as revealed by its insensitivity to low and high doses of alpha-amanitin. The size of the in vitro transcript was mostly larger than 28S at 10 minute incubation and became smaller as incubation proceeded. When [gamma-32P]ATP was included in the reaction mixture, 32P radioactivity was incorporated into RNA suggesting the possible initiation of transcription in this system. However, analysis of the terminal nucleotide of the transcript revealed that the incorporation of radioactivity from [gamma-32P]ATP was not due to the initiation of transcription but due to polynucleotide kinase activity in the nucleolar preparation. These results demonstrate that the incorporation of radioactivity from [gamma-32P] labeled nucleoside triphosphates cannot necessarily be regarded as an index of the initiation of transcription.
...
PMID:Properties of in vitro transcription by isolated Xenopus oocyte nucleoli. 45 Jul 18

Yeast tRNA ligase, from Saccharomyces cerevisiae, is one of the protein components that is involved in the splicing reaction of intron-containing yeast precursor tRNAs. It is an unusual protein because it has three distinct catalytic activities. It functions as a polynucleotide kinase, as a cyclic phosphodiesterase, and as an RNA ligase. We have studied the binding interactions between ligase and precursor tRNAs containing two photoreactive uridine analogues, 4-thiouridine and 5-bromouridine. When irradiated with long ultraviolet light, RNA containing these analogues can form specific covalent bonds with associated proteins. In this paper, we show that 4-thiouridine triphosphate and 5-bromouridine triphosphate were readily incorporated into a precursor tRNA(Phe) that was synthesized, in vitro, with bacteriophage T7 RNA polymerase. The analogue-containing precursor tRNAs were authentic substrates for the two splicing enzymes that were tested (endonuclease and ligase), and they formed specific covalent bonds with ligase when they were irradiated with long-wavelength ultraviolet light. We have determined the position of three major cross-links and one minor cross-link on precursor tRNA(Phe) that were located within the intron and near the 3' splice site. On the basis of these data, we present a model for the in vivo splicing reaction of yeast precursor tRNAs.
...
PMID:Binding interactions between yeast tRNA ligase and a precursor transfer ribonucleic acid containing two photoreactive uridine analogues. 285 71

DNA-dependent ATPase IV has been purified to near homogeneity from the Novikoff rat hepatoma. The enzyme is devoid of DNA polymerase, RNA polymerase, exonuclease, endonuclease, phosphomonoesterase, 3'- or 5'-phosphodiesterase, polynucleotide kinase, protein kinase, topoisomerase, helicase or DNA reannealing activities at a detection level of 10(-5) to 10(-7) relative to the ATPase activity. The enzyme is a monomer of Mr 110,000, has a sedimentation coefficient of 5.9 S, a Stokes radius of 40 A and a frictional coefficient of 1.32. In the presence of Mg2+ ion and a polynucleotide effector, ATPase IV hydrolyzes either ATP or dATP to the nucleoside diphosphate plus Pi. Other ribo- or deoxyribonucleoside triphosphates are not substrates. ATPase IV utilizes double-stranded DNA and single-stranded DNA as effector; however, it does not utilize poly(dT). The Km for dsDNA or ssDNA is 2.2 microM (nucleotide). A variety of ATP analogues were found to be competitive inhibitors of ATPase IV.
...
PMID:Purification and enzymological characterization of DNA-dependent ATPase IV from the Novikoff hepatoma. 296 5

Globin messenger RNA, isolated from human peripheral blood reticulocytes, was transcribed into complementary DNA by use of the RNA-dependent DNA polymerase of avian myeloblastosis virus. The complementary DNA was then transcribed into (32)P-labeled complementary RNA by E. coli RNA polymerase in the presence of alpha-(32)P-labeled ribonucleoside triphosphates. The fingerprint pattern obtained from ribonuclease T1 digests of human globin complementary RNA was specific and reproducible. Different patterns were obtained from digests of duck, mouse, and rabbit globin complementary RNA. The fingerprint patterns obtained from digests of purified natural human 10S globin messenger RNA, labeled in vitro with (125)I or with [gamma-(32)P]ATP and polynucleotide kinase, were similar to that of the complementary RNA but contained some additional oligonucleotides. Sufficient nucleotide sequence information has been obtained from about 50% of the intermediate sized oligonucleotides (8-14 base residues long), to make possible examination of correspondence between these nucleotide sequences and globin amino-acid sequences. Approximately 70% of these oligonucleotide sequences can be matched to unique amino-acid sequences in the alpha- or beta-globin chains. The other 30% do not match known amino-acid sequences and presumably correspond to untranslated portions of the mRNA; some of these sequences, however, can be matched to amino-acid sequence in the abnormally long segment of the alpha chain of hemoglobin Constant Spring, which is thought to result from a chain-termination mutation.
...
PMID:Nucleotide sequences of human globin messenger RNA. 413 9

The major 5'-termini of human adenovirus type 2 early gene block 4 mRNA were sequenced. Poly(A+) polyribosomal RNA was isolated from Ad2 early infected cells, the 5'-terminal m7GPPP removed and the 5'-OH of the penultimate 2'-0-methylated nucleotide labeled with [gamma-32P]ATP using polynucleotide kinase. Ad2 E4 mRNA was purified by hybridization to the Ad2 EcoRI-C fragment and was digested with RNase T1. The resulting oligonucleotides were resolved by two dimensional paper electrophoresis-homochromatography. Four major and 3-4 minor 5'-terminal sequences were identified and characterized. The sequence of the 5'-terminal structures of the major four termini are: (1) m7GpppUmU(m)UUACACUGp, (2) m7GpppUmU(m)UACACUGp, (3) m7GpppUmU(m)ACACUGp, and (4) m7Gppp(m6)AmC(m)ACUGp. These major 5'-terminal sequences were aligned with nucleotide 325, 326, 327, and 329 from the righthand end of the known Ad2 DNA sequence (1) in the region mapped as the 5'-terminus of E4 mRNA by electron microscopy (2,3) and S1 nuclease-gel (4) mapping. Two potential ribosomal binding sites and an initiator codon were found at 40 to 65 nucleotides and about 80 nucleotides, respectively, from these heterogenous 5'-termini. Ad2 E4 major mRNA species appear to be unique since mRNA molecules initiate at a pyrimidine, perhaps by RNA polymerase stuttering, or they are products of an unusual type of RNA processing.
...
PMID:Nucleotide sequences and mapping of novel heterogenous 5'-termini of adenovirus 2 early region 4 mRNA. 616 92

By a combination of chemical and enzymatic methods, a 75 base pair DNA duplex containing the sequence of the lambda PR promoter including the OR1 and OR2 cI repressor binding sites was synthesized. The solid support phosphite triester procedure (Caruthers, M. H. et al., Cold Spring Harbor Symposia on Quantitative Biology XLVII, in press) was used for the synthesis of oligonucleotides comprising the sequence. We report here an adaptation of the method of DNA synthesis in test tubes. Assembly of the oligonucleotides involved the use of T4 polynucleotide kinase and T4 DNA ligase. We show that the synthetic DNA is recognized by RNA polymerase and cI repressor in a manner identical to the same control region contained on a restriction fragment isolated from bacteriophage lambda DNA. Our synthetic approach using chemically synthesized promoter variants is thus suitable for studies probing the function of promoters.
...
PMID:Chemical synthesis and biochemical reactivity of bacteriophage lambda PR promoter. 630 Jul 67

We found a novel inhibitor specific to eukaryotic DNA polymerase epsilon(pol epsilon) from plant cultured cells, Nicotina tabacum L. The compound (compound 1) was a dipeptide alcohol, L-homoserylaminoethanol. The 50% inhibition of pol epsilon activity by the compound was 43.6 microg/mL, and it had almost no effect on the activities of the other eukaryotic DNA polymerases such as alpha, beta, gamma and delta, prokaryotic DNA polymerases, nor DNA metabolic enzymes such as human telomerase, human immunodeficiency virus type 1 reverse transcriptase, T7 RNA polymerase, human DNA topoisomerase I and II, T4 polynucleotide kinase and bovine deoxyribonuclease I. Kinetic studies showed that inhibition of pol epsilon by the compound was non-competitive with respect to both template-primer DNA and nucleotide substrate. We succeeded in chemically synthesizing the stereoisomers, L-homoserylaminoethanol and D-homoserylaminoethanol, and found both were effective to the same extent. The IC(50) values of L- and D-homoserylaminoethanols for pol epsilon were 42.0 and 41.5 microg/mL, respectively. This represents the second discovery of a pol epsilon-specific inhibitor, and the first report on a water-soluble peptide-like compound as the inhibitor, which is required in biochemical studies of pol epsilon.
...
PMID:L-Homoserylaminoethanol, a novel dipeptide alcohol inhibitor of eukaryotic DNA polymerase from a plant cultured cells, Nicotina tabacum L. 1498 Jun 8

A simple strategy is reported for 5'-adenylation of nearly any RNA sequence of indefinite length. The 5'-adenylated product (5'-AppRNA) is an activated RNA that is structurally similar to 5'-triphosphorylated RNA, which is usually prepared by in vitro transcription using T7 RNA polymerase. In the new 5'-adenylation strategy, the RNA substrate is first 5'-monophosphorylated either by T4 polynucleotide kinase, by in vitro transcription in the presence of excess GMP, or by appropriate derivatization during solid-phase synthesis. The RNA is then 5'-adenylated using ATP and T4 RNA ligase, in an interrupted version of the natural adenylation-ligation mechanism by which T4 RNA ligase joins two RNA substrates. Here, the final ligation step of the mechanism is inhibited with complementary DNA blocking oligonucleotide(s) that permit adenylation to occur with good yield. The 5'-AppRNA products of this approach should be valuable as activated RNAs for in vitro selection experiments as an alternative to 5'-triphosphorylated RNAs, among other likely applications. The 5'-terminal nucleotide of an RNA substrate to be adenylated using the new method is not restricted to guanosine, in contrast to 5'-triphosphorylated RNA prepared by in vitro transcription. Therefore, using the new approach, essentially any RNA obtained from solid-phase synthesis or other means can be activated by 5'-adenylation in a practical manner.
...
PMID:Practical and general synthesis of 5'-adenylated RNA (5'-AppRNA). 1503 82

Traditional Chinese medicinal plants are a treasure house for screening novel inhibitors of DNA polymerases and DNA topoisomerases from mammals; in the present study, nine lanostane-type triterpene acids were found in sclerotium of Poria cocos. Among the nine compounds, only dehydroebriconic acid could potently inhibit DNA topoisomerase II (topo II) activity (IC(50) = 4.6 microM), while the compound moderately inhibited the activities of DNA polymerases alpha, beta, gamma, delta, epsilon, eta, iota, kappa and lambda only from mammals, to similar extents. Another compound, dehydrotrametenonic acid, also showed moderate inhibitory effects against topo II (IC(50) = 37.5 microM) and weak effects against all the polymerases tested. Both compounds showed no inhibitory effect against topo I, higher plant (cauliflower) DNA polymerase I (alpha-like polymerase) or II (beta-like polymerase), calf thymus terminal deoxynucleotidyl transferase, human immunodeficiency virus type-1 reverse transcriptase, prokaryotic DNA polymerases such as the Klenow fragment of E. coli DNA polymerase I, Taq DNA polymerase and T4 DNA polymerase, or DNA metabolic enzymes such as T 7 RNA polymerase, T4 polynucleotide kinase and bovine deoxyribonuclease I. These findings suggest that dehydroebriconic acid and dehydrotrametenonic acid should be designated as topo II-preferential inhibitors, although they also moderately inhibited all the mammalian DNA polymerases tested. Both dehydrotrametenonic acid and dehydroebriconic acid could prevent the growth of human gastric cancer cells, and their LD(50) values were 63.6 and 38.4 microM, respectively. The cells were halted at the G1 phase in the cell cycle. The relation between the structure of triterpene acids and their inhibitory activities is discussed.
...
PMID:A novel DNA topoisomerase inhibitor: dehydroebriconic acid, one of the lanostane-type triterpene acids from Poria cocos. 1507 95


1 2 3 Next >>

---