The nuclear DNA-dependent ribonucleic acid polymerases of the dermatophytic fungus Microsporum gypseum

1976 ◽  
Vol 22 (2) ◽  
pp. 177-181
Author(s):  
Barbara C. Dill ◽  
J. J. Stock
Keyword(s):  
Ribonucleic Acid ◽  
Nuclear Dna ◽  
Rna Polymerases ◽  
Microsporum Gypseum ◽  
Nuclear Extracts ◽  
Eukaryotic Organisms ◽  
Enzyme Species

The DNA-dependent RNA polymerases of the dermatophytic fungus Microsporum gypseum were partially characterized. Nuclear extracts prepared from vegetative mycelia were fractionated by DEAE-Sephadex chromatography into three enzyme species which resembled in most of their characteristics those of other eukaryotic organisms.

Specificity of corticotrophin-induced increase in mitochondrial ribonucleic acid

1964 ◽  
Vol 206 (5) ◽  
pp. 1156-1160 ◽  
Author(s):  
Morton B. Sigel ◽  
J. Thomas Dowling
Keyword(s):  
Nucleic Acid ◽  
Ribonucleic Acid ◽  
Nuclear Dna ◽  
Weight Ratio ◽  
Intermediary Metabolism ◽  
Female Rats ◽  
Nucleic Acid Content ◽  
Mitochondrial Rna ◽  
Percentage Increase ◽  
Specific Increase

Ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) were measured in subcellular fractions of pooled adrenals removed from rats 4 hr after injection of agents known to affect or suspected of altering adrenal intermediary metabolism. Corticotrophin (2 µ) increased mitochondrial RNA 29% over that of saline-injected animals and 74% over uninjected controls. Nuclear DNA and nuclear and microsomal RNA were unchanged. Thyrotrophin (2 µ), growth hormone (1 µ), chorionic gonadotrophin (500 µ), triiodothyronine (25 µg), p-dinitrophenol (50 µg), crude parathyroid hormone (10 µ), and vasopressin (0.4 µ) failed to affect either nucleic acid. The mitochondrial-adrenal weight ratio increased only in corticotrophin-treated animals. The percentage increase of mitochondrial RNA exceeded that of mitochondrial weight. Conjugated estrogen was the only other agent that produced a response. One, five, and ten micrograms increased DNA in spayed female rats while 50 µg produced no effect. Estrogen presumably affected cell division. A part of the sequential response of adrenal intermediary metabolism to corticotrophin includes a specific increase in the nucleic acid content of that organelle associated anatomically with steroidogenesis.

scholarly journals Ribonuclease "XlaI," an activity from Xenopus laevis oocytes that excises intervening sequences from yeast transfer ribonucleic acid precursors.

1981 ◽  
Vol 1 (3) ◽  
pp. 269-280 ◽  
Author(s):  
A Otsuka ◽  
A de Paolis ◽  
G P Tocchini-Valentini
Keyword(s):  
Xenopus Laevis ◽  
Ribonucleic Acid ◽  
Rnase A ◽  
Xenopus Laevis Oocytes ◽  
Cleavage Sites ◽  
Reaction Products ◽  
Yeast Trna ◽  
Intervening Sequences ◽  
Nuclear Extracts ◽  
Hydroxyl Termini

A ribonuclease (RNase) activity, RNase "XlaI," responsible for the excision of intervening sequences from two yeast transfer ribonucleic acid (tRNA) precursors, pre-tRNA(Tyr) and pre-tRNA(3Leu), has been purified 54-fold from nuclear extracts of Xenopus laevis oocytes. The RNase preparation is essentially free of contaminating RNase. A quantitative assay for RNase XlaI was developed, and the reaction products were characterized. RNase XlaI cleavage sites in the yeast tRNA precursors were identical to those made by yeast extracts (including 3'-phosphate and 5'-hydroxyl termini). Cleavage of pre-tRNA(3Leu) by RNase XlaI and subsequent ligation of the half-tRNA molecules do not require removal of the 5' leader or 3' trailer sequences.

Immunological relationships between Artemia RNA polymerases and between RNA polymerases II from different eukaryotic organisms

1987 ◽  
Vol 76 (2) ◽  
Author(s):  
Victor D�az ◽  
Miguel Quintanilla ◽  
Jes�s Cruces ◽  
Jaime Renart ◽  
Jes�s Sebasti�n
Keyword(s):  
Rna Polymerases ◽  
Eukaryotic Organisms

A unified matrix hypothesis of DNA-directed morphogenesis, protodynamism and growth control1

1989 ◽  
Vol 9 (2) ◽  
pp. 157-188 ◽  
Author(s):  
Klaus Scherrer
Keyword(s):  
Nuclear Dna ◽  
Theoretical Concept ◽  
Structure And Function ◽  
Protein Coding ◽  
Basic Proposition ◽  
C Value ◽  
Eukaryotic Organisms ◽  
And Function ◽  
Chromosome Organisation ◽  
Morphological Patterns

A theoretical concept is proposed, in order to explain some enigmatic aspects of cellular and molecular biology of eukaryotic organisms. Among these are the C-value paradox of DNA redundancy, the correlation of DNA content and cell size, the disruption of genes at DNA level, the “Chromosome field” data of Lima de Faria (Hereditas93:1, 1980), the “quantal mitosis” proposition of Holtzer et al. (Curr. Top. Dev. Biol.7:229 1972), the inheritance of morphological patterns, the relations of DNA and chromosome organisation to cellular structure and function, the molecular basis of speciation, etc. The basic proposition of the “Unified Matrix Hypothesis” is that the nuclear DNA has a direct morphogenic function, in addition to its coding function in protein synthesis. This additional genetic information is thought to be largely contained in the non-protein coding transcribed DNA, and in the untranscribed part of the genome.

Inhibition of nuclear DNA-dependent RNA polymerases from mouse ascites tumors and liver by glycerol

1977 ◽  
Vol 55 (10) ◽  
pp. 1117-1120 ◽  
Author(s):  
D. G. R. Blair
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Mouse Liver ◽  
Nuclear Dna ◽  
Ehrlich Ascites Carcinoma ◽  
Rna Polymerases ◽  
Ehrlich Carcinoma ◽  
Ehrlich Ascites ◽  
Mouse Ascites ◽  
Ascites Tumors

Nuclear DNA-dependent RNA polymerases were isolated from Ehrlich ascites carcinoma, TA3 ascites adenocarcinoma, and mouse liver and tested for inhibition by glycerol. The results confirm the finding of Smith and Duerksen ((1975) Biochem. Biophys. Res. Commun. 67, 916–923) that glycerol may inhibit nuclear RNA polymerase II, but because different grades of glycerol inhibited mouse liver RNA polymerase IIa to different extents, it is suggested that an inhibitory contaminant is present. RNA polymerases IIa and IIb from the two tumors and mouse liver were proportionately inhibited by A.C.S. reagent-grade glycerol at concentrations above 10%. RNA polymerase Ia from liver and the TA3 tumor was not inhibited by any concentration of glycerol tested (2–32.3%), but RNA polymerase Ia from Ehrlich carcinoma was inhibited by glycerol concentrations above 16%.

scholarly journals Eukaryotic Multi-subunit DNA dependent RNA Polymerases: An Insight into Their Active Sites and Catalytic Mechanism

2019 ◽  
pp. 1-60
Author(s):  
Peramachi Palanivelu
Keyword(s):  
Amino Acids ◽  
Metal Binding ◽  
Active Sites ◽  
Dna Polymerases ◽  
Rna Polymerases ◽  
Site Directed Mutagenesis ◽  
Binding Motif ◽  
Conserved Motifs ◽  
X Ray ◽  
Eukaryotic Organisms

Aim: To analyze the most complex multi-subunit (MSU) DNA dependent RNA polymerases (RNAPs) of eukaryotic organisms and find out conserved motifs, metal binding sites and catalytic regions and propose a plausible mechanism of action for these complex eukaryotic MSU RNAPs, using yeast (Saccharomyces cerevisiae) RNAP II, as a model enzyme. Study Design: Bioinformatics, Biochemical, Site-directed mutagenesis and X-ray crystallographic data were analyzed. Place and Duration of Study: School of Biotechnology, Madurai Kamaraj University, Madurai, India, between 2007- 2013. Methodology: Bioinformatics, Biochemical, Site-directed mutagenesis (SDM) and X-ray crystallographic data of the enzyme were analyzed. The advanced version of Clustal Omega was used for protein sequence analysis of the MSU DNA dependent RNAPs from various eukaryotic sources. Along with the conserved motifs identified by the bioinformatics analysis, the data already available by biochemical and SDM experiments and X-ray crystallographic analysis of these enzymes were used to confirm the possible amino acids involved in the active sites and catalysis. Results: Multiple sequence alignment (MSA) of RNAPs from different eukaryotic organisms showed a large number of highly conserved motifs among them.  Possible catalytic regions in the catalytic subunits of the yeast Rpb2 (= β in eubacteria) and Rpb1 (= β’ in eubacteria) consist of an absolutely conserved amino acid R, in contrast to a K that was reported for DNA polymerases and single subunit (SSU) RNAPs. However, the invariant ‘gatekeeper/DNA template binding’ YG pair that was reported in all SSU RNAPs, prokaryotic MSU RNAPs and DNA polymerases is also highly conserved in eukaryotic Rpb2 initiation subunits, but unusually a KG pair is found in higher eukaryotes including the human RNAPs. Like the eubacterial initiation subunits of MSU RNAPs, the eukaryotic initiation subunits, viz. Rpb2, exhibit very similar active site and catalytic regions but slightly different distance conservations between the template binding YG/KG pair and the catalytic R. In the eukaryotic initiation subunits, the proposed catalytic R is placed at the -9th position from the YG/KG pair and an invariant R is placed at -5 which are implicated to play a role in nucleoside triphosphate (NTP) selection as reported for SSU RNAPs (viral family) and DNA polymerases. Similarly, the eukaryotic elongation subunits (Rpb1) are also found to be very much homologous to the elongation subunits (β’) of prokaryotes. Interestingly, the catalytic regions are highly conserved, and the metal binding sites are absolutely conserved as in prokaryotic MSU RNAPs. In eukaryotes, the template binding YG pair is replaced with an FG pair. Another interesting observation is, similar to the prokaryotic β’ subunits, in the eukaryotic Rpb1 elongation subunits also, the proposed catalytic R is placed double the distance, i.e., -18 amino acids downstream from the FG pair unlike in the SSU RNAPs and DNA polymerases where the distance is only -8 amino acids downstream from the YG pair. Thus, the completely conserved FG pair, catalytic R with an invariant R, at -6th position are proposed to play a crucial role in template binding, NTP selection and polymerization reactions in the elongation subunits of eukaryotic MSU RNAPs. Moreover, the Zn binding motif with the three completely conserved Cs is also highly conserved in the eukaryotic elongation subunits. Another important difference is that the catalytic region is placed very close to the N-terminal region in eukaryotes. Conclusions: Unlike reported for the DNA polymerases and SSU RNA polymerases, the of eukaryotic MSU RNAPs use an R as the catalytic amino acid and exhibit a different distance conservation in the initiation and elongation subunits. An invariant Zn2+ binding motif found in the Rpb1 elongation subunits is proposed to participate in proof-reading function. Differences in the active sites of bacterial and human RNA polymerases may pave the way for the design of new and effective drugs for many bacterial infections, including the multidrug resistant strains which are a global crisis at present.

scholarly journals Defining the divergent enzymatic properties of RNA polymerases I and II

2020 ◽  
pp. jbc.RA120.015904
Author(s):  
Ruth Q. Jacobs ◽  
Zachariah M Ingram ◽  
Aaron L. Lucius ◽  
David A. Schneider
Keyword(s):  
Nuclear Dna ◽  
In Vitro Transcription ◽  
Rna Polymerases ◽  
Enzymatic Properties ◽  
Experimental Conditions ◽  
Pol Ii ◽  
Pol I ◽  
Nucleotide Addition ◽  
Addition Rate

Eukaryotes express at least three nuclear DNA-dependent RNA polymerases (Pols) responsible for synthesizing all RNA required by the cell. Despite sharing structural homology, they have functionally diverged to suit their distinct cellular roles. Although the Pols have been studied extensively, direct comparison of their enzymatic properties is difficult since studies are often conducted under disparate experimental conditions and techniques. Here, we directly compare and reveal functional differences between Saccharomyces cerevisiae Pols I and II using a series of quantitative in vitro transcription assays. We find that Pol I single and multi-nucleotide addition rate constants are faster than those of Pol II. Pol I elongation complexes (ECs) are less stable than Pol II ECs, and Pol I is more error prone than Pol II. Collectively, these data show that the enzymatic properties of the Pols have diverged over the course of evolution, optimizing these enzymes for their unique cellular responsibilities.

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