Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An improved method is described for the purification of the DNA-dependent RNA polymerase [ribonucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6] from Escherichia coli. The method involves lysozyme-sodium deoxycholate lysis, low-speed centrifugation, precipitation with Polymin P, elution from the Polymin P precipitate, ammonium sulfate precipitation, and chromatography on DNA-cellulose and Bio-Gel A 5m. RNA polymerase is purified to electrophoretic homogeneity in 2 days with a recovery of 45%, resulting in a yield of 250 mg of holoenzyme from 500 g of cells.
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PMID:A procedure for the rapid, large-scall purification of Escherichia coli DNA-dependent RNA polymerase involving Polymin P precipitation and DNA-cellulose chromatography. 110 52

An improved method for the purification of the alpha-amanitin-sensitive deoxyribonucleic acid dependent ribonucleic acid polymerase [ribonucleosidetriphosphate:RNA-nucleotidyltransferase, EC 2.7.7.6-A1 (RNA polymerase II or RNA polymerase B) from wheat germ is presented. The method involves homogenization of wheat germ in a buffer of moderate ionic strength, precipitation of RNA polymerase with Polymin P (a polyethylenimine), elution of RNA polymerase from the Polymin P precipitate, ammonium sulfate precipitation, and chromatography on DEAE-cellulose and phosphocellulose. RNA polymerase II is purified over 4000-fold with a 60% recovery, resulting in a yield of 25-30 mg of RNA polymerase from 1 kg of starting material.
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PMID:A new method for the large-scale purification of wheat germ DNA-dependent RNA polymerase II. 118 7

A procedure has been developed for a large scale and rapid isolation of RNA polymerase I (EC 2.7.7.6) of Tetrahymena pyriformis. The enzyme is precipitated from the cell homogenate by Polymin P, extracted from the sediment and separated from RNA polymerase II by a treatment with phosphocellulose. The further purification procedure involves sedimentation in glycerol gradients and chromatography on heparin-Sepharose and DEAE-Sephadex. The last step achieved the separation of RNA polymerase I from RNA polymerase III. On the basis of different criteria RNA polymerase I is assumed to consist of two large subunits of 180 and 118 kDa and nine subunits smaller than 50 kDa. Additional polypeptides have been identified which are associated with RNA polymerase I but are not found in integral stoichiometric amounts. Except for certain minor differences RNA polymerase I purified from the cell homogenate shows the same structure as the enzyme obtained from isolated macronuclei (Mueller et al., 1985).
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PMID:Large scale isolation of RNA polymerase I of Tetrahymena pyriformis and the identification of polymerase-associated polypeptides. 310 89

A procedure for the purification of RNA polymerase from vegetative cells of the filamentous cyanobacterium Anabaena 7120 is described. Polyethyleneimine precipitation followed by gel filtration and affinity chromatography steps results in greater than 99% purification with 46% yield. The enzyme has a novel core component of Mr = 66,000, designated gamma, in addition to the typical prokaryotic beta'beta alpha 2 core enzyme. The sigma subunit has been identified by reconstitution of specific transcriptional activity from core enzyme and gel-purified sigma. In transcription assays, this RNA polymerase initiates at a number of Anabaena vegetative cell promoters, as well as from a bacteriophage T4 early promoter, but does not initiate at nitrogen fixation (nif) promoters used in heterocysts. The promoter specificity of Anabaena RNA polymerase is compared with that of Escherichia coli RNA polymerase.
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PMID:Purification and characterization of RNA polymerase from the cyanobacterium Anabaena 7120. 311 88

DNA-dependent RNA polymerase from vegetative cells of the gram-negative, fruiting bacterium Myxococcus xanthus was purified more than 300-fold by a modified Burgess procedure (Lowe et al., Biochemistry 18:1344-1352, 1979), using Polymin P precipitation, 40 to 65% saturated ammonium sulfate fractional precipitation, double-stranded DNA cellulose chromatography, A5m gel filtration chromatography, and single-stranded DNA agarose chromatography. The last step separated the RNA polymerase into a core fraction and an enriched holoenzyme fraction. The core enzyme showed a subunit structure similar to that of the Escherichia coli polymerase, as follows: beta' and beta (145,000 and 140,000 daltons, respectively) and alpha (38,000 daltons). A comparison of the core enzyme and the holoenzyme implicated two polypeptides as possible sigma subunits. These polypeptides were closely related, as indicated by peptide analysis. M. xanthus RNA polymerase was capable of transcribing DNAs from E. coli phages T7, T4, and lambda, Bacillus subtilis phage phi 29, and M. xanthus phages Mx1, Mx4, and Mx8. Transcription of T7 and phi 29 DNAs was stimulated by KCl, whereas transcription of Mx1, Mx4, and Mx8 DNAs was inhibited by KCl. Magnesium ion dependence, rifampin and heparin sensitivities, and spermidine stimulation of M. xanthus RNA polymerase activity were similar to those found with E. coli RNA polymerase. The pH optimum of M. xanthus RNA polymerase activity was more basic than that of E. coli polymerase. M. xanthus RNA polymerase was capable of selective transcription in vitro when DNAs from phages T7 delta 111, phi 29, and Mx1 were used. The molecular weights of the resulting phage RNA transcripts made by M. xanthus RNA polymerase (as determined by agarose-acrylamide slab gel electrophoresis) were the same as the molecular weights of the transcripts synthesized by E. coli RNA polymerase. No discrete transcripts were detected as the in vitro RNA products of M. xanthus phage Mx4 and Mx8 DNA transcription. Southern transcript synthesized by M. xanthus RNA polymerase. Three transcripts (transcripts A, B, and C; molecular weights, 2.55 X 10(6), 1.95 X 10(6), and 1.56 X 10(6), respectively) were identified as in vitro RNA products of M. xanthus phage Mx1 DNA transcription when either E. coli or M. xanthus RNA polymerase was used. A Southern blot hybridization analysis indicated that the E. coli RNA polymerase and the M. xanthus RNA polymerase transcribe common SalI restriction fragments of Mx1 DNA.
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PMID:RNA polymerase of Myxococcus xanthus: purification and selective transcription in vitro with bacteriophage templates. 680 51

DNA-Dependent RNA polymerase (EC 2.7.7.6) was isolated from Thermomonospora curvata. The purification steps included precipitation with Polymin P, elution of the precipitate with 0.3 mol/L KCl, precipitation with ammonium sulfate, affinity chromatography on heparin-agarose and molecular filtration on Biogel A 1.5 m.
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PMID:Isolation of DNA-dependent RNA polymerase from the thermophilic actinomycete Thermomonospora curvata. 818 83

Purification of DNA-dependent RNA polymerase from exponentially growing cells of the cyanobacterium Synechococcus sp. is described in cultures grown at normal temperature (39 degrees C) and after heat shock (HS) (47 degrees C). Polyethyleneimine precipitation followed by chromatography and gel filtration steps results in a 39% yield. The enzyme has a component of molar mass of 43 kDa, designated sigma, in addition to the typical procaryotic beta' beta alpha 2 and gamma. The results suggest that Synechococcus RNA polymerase is similar to that of cyanobacterial and E. coli RNA polymerases. Electrophoresis of the HS preparation showed that the enzyme has a component of 18 kDa. This suggests the existence of a functional relationship between this protein and the HS response of Synechococcus RNA polymerase, probably in salvaging denatured RNA polymerase or helping to regain its native structure.
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PMID:Effect of heat shock on DNA-dependent RNA polymerase from the cyanobacterium Synechococcus sp. 913 93