scholarly journals Convolution analysis of transcription by yeast DNA-dependent ribonucleic acid polymerase A. A mathematical method for studying ribonucleic acid chain elongation

1979 ◽  
Vol 177 (3) ◽  
pp. 825-831
Author(s):  
C S Cooper ◽  
R V Quincey
Keyword(s):  
Mathematical Method ◽  
Rna Polymerase ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Integral Solution ◽  
Chain Elongation ◽  
Enzyme Molecule ◽  
Convolution Integral ◽  
Calf Thymus ◽  
Biphasic Profile

The rate of initiation of RNA synthesis catalysed by yeast RNA polymerase A on native calf thymus DNA decayed exponentially with a half-life of about 4.3 min. The rate constant for initiation was unaffected by preincubating the enzyme with DNA, or by decreasing the concentration of GTP 4-fold. The rate of RNA synthesis was constant for 15–20 min and then decreased. Each enzyme molecule made no more than one RNA molecule. In this situation, initiation, elongation and total RNA synthesis are related by a convolution integral. Solution of the convolution integral revealed that the rate of elongation was apparently biphasic. Analysis of the size of the RNA product showed that this biphasic profile arose because most but not all of the enzyme stopped RNA synthesis soon after initiation.

Action of Trifluralin on Chromatin Activity in Corn and Soybean

Weed Science ◽  
1972 ◽  
Vol 20 (4) ◽  
pp. 364-366 ◽  
Author(s):  
Donald Penner ◽  
Roy W. Early
Keyword(s):  
Escherichia Coli ◽  
Zea Mays ◽  
Glycine Max ◽  
Rna Polymerase ◽  
Melting Temperature ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Subsequent Reduction

Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 10−5M applied to etiolated corn(Zea maysL. ‘Michigan 500′) seedlings 6 or 12 hr before the isolation of chromatin from the roots markedly reduced ribonucleic acid (RNA) synthesis supported by the chromatin. The addition ofEscherichia coliRNA polymerase failed to overcome the inhibition. Trifluralin increased the melting temperature of the chromatin. The presence of trifluralin during the isolation and reaction procedure inhibited RNA synthesis indicating possible trifluralin binding to the chromatin with subsequent reduction of template availability for transcription. Trifluralin did not inhibit chromatin activity in soybean [Glycine max(L.) Merr. ‘Hark’] seedlings.

scholarly journals Decreased ribonucleic acid synthesis in isolated rat liver nuclei during starvation

1970 ◽  
Vol 120 (2) ◽  
pp. 381-384 ◽  
Author(s):  
D. Rickwood ◽  
H. G. Klemperer
Keyword(s):  
Rna Polymerase ◽  
Ammonium Sulphate ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Isolated Nuclei ◽  
Isolated Rat Liver ◽  
Liver Nuclei ◽  
Isolated Rat

1. Isolated nuclei from starved rats showed a lowered incorporation of [14C]UMP into RNA. 2. The Mg2+-dependent incorporation was decreased by 30% after 1 day of starvation, but incorporation in the presence of Mn2+ and ammonium sulphate decreased only after longer periods of starvation. 3. RNA synthesis by nuclei in the presence of excess of added RNA polymerase was unchanged after 1 day of starvation and was inhibited by 20% after 4 days. 4. The capacity of nuclei to bind actinomycin D was unchanged after 1 day and was decreased by 20% after 4 days of starvation.

scholarly journals Antimicrobial Properties and Mode of Action of the Pyrrothine Holomycin

2001 ◽  
Vol 45 (2) ◽  
pp. 532-539 ◽  
Author(s):  
Brunello Oliva ◽  
Alexander O'Neill ◽  
Jenny M. Wilson ◽  
Peter J. O'Hanlon ◽  
Ian Chopra
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Antimicrobial Properties ◽  
Stringent Response ◽  
Active Species ◽  
Chain Elongation ◽  
Whole Cells ◽  
E Coli ◽  
Eukaryotic Microorganisms ◽  
Kinetics Of

ABSTRACT Holomycin, a member of the pyrrothine class of antibiotics, displayed broad-spectrum antibacterial activity, inhibiting a variety of gram-positive and gram-negative bacteria, with the exception ofEnterobacter cloacae, Morganella morganii, andPseudomonas aeruginosa. The antibiotic lacked activity against the eukaryotic microorganisms Saccharomyces cerevisiae and Candida kefyr. Holomycin exhibited a bacteriostatic response against Escherichia coli that was associated with rapid inhibition of RNA synthesis in whole cells. Inhibition of RNA synthesis could have been a secondary consequence of inhibiting tRNA aminoacylation, thereby inducing the stringent response. However, the levels of inhibition of RNA synthesis by holomycin were similar in a stringent and relaxed pair of E. coli strains that were isogenic except for the deletion of therelA gene. This suggests that inhibition of RNA synthesis by holomycin could reflect direct inhibition of DNA-dependent RNA polymerase. Examination of the effects of holomycin on the kinetics of the appearance of β-galactosidase in induced E. colicells was also consistent with inhibition of RNA polymerase at the level of RNA chain elongation. However, holomycin only weakly inhibitedE. coli RNA polymerase in assays using synthetic poly(dA-dT) and plasmid templates. Furthermore, inhibition of RNA polymerase was observed only at holomycin concentrations in excess of those required to inhibit the growth of E. coli. It is possible that holomycin is a prodrug, requiring conversion in the cell to an active species that inhibits RNA polymerase.

scholarly journals Synthesis of ribonucleic acid in purine-deficient Escherichia coli and a comparison with the effects of amino acid starvation

1970 ◽  
Vol 120 (1) ◽  
pp. 125-132 ◽  
Author(s):  
N. F. Varney ◽  
Gillian A. Thomas ◽  
K. Burton
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Adenine Nucleotides ◽  
Amino Acid Starvation ◽  
Guanine Nucleotides ◽  
Purine Nucleotides ◽  
Acid Control

1. Experiments with rifampicin and stringent strains of Escherichia coli (pro−purB−rel+) indicate that purine deficiency does not decrease and may considerably increase the potential for RNA synthesis by RNA polymerase molecules that are bound to DNA and have already commenced transcription. 2. DNA–RNA hybridization experiments indicate that purine starvation increases the distribution of bound RNA polymerase molecules between the cistrons for mRNA and those for stable RNA. 3. Synthesis of β-galactosidase mRNA is more dependent on the ability to synthesize guanine nucleotides than on the ability to synthesize adenine nucleotides. 4. Amino acid starvation tends to decrease the potential for RNA synthesis by RNA polymerase molecules bound to DNA. 5. Since this effect differs from that due to purine starvation, amino acid control of RNA synthesis does not appear to operate solely by causing a deficiency of purine nucleotides. 6. The results are discussed in terms of the ability to initiate RNA chains and to extend them under different circumstances.

scholarly journals The role of subunits in yeast DNA-dependent ribonucleic acid polymerase A

1979 ◽  
Vol 181 (2) ◽  
pp. 301-308 ◽  
Author(s):  
C S Cooper ◽  
R V Quincey
Keyword(s):  
Dna Binding ◽  
Rna Polymerase ◽  
Temperature Dependence ◽  
Ribonucleic Acid ◽  
Specific Activity ◽  
Calf Thymus Dna ◽  
Calf Thymus

The properties of RNA polymerase A, which lacked the subunits of 48 000, 37 000 and 16 000 mol. wt., were compared with those of RNA polymerase A by using native calf thymus DNA as the template. The results showed that: (1) the specific activity of RNA polymerase A was about one-third that of RNA polymerase A; (2) more than 80% of RNA polymerase A, but only about 25% of RNA polymerase A, made RNA; (3) initiation by RNA polymerase A, but not by RNA polymerase A, began after a lag of 2 min; (4) the temperature-dependence for productive binding to DNA was greater for RNA polymerase A; (5) the apparent Km for UTP was greater for RNA polymerase A. These results support the supposition that the subunits missing from RNA polymerase A are involved in DNA binding [Huet, Dezélée, Iborra, Buhler, Sentenac & Fromageot (1976) Biochimie 58, 71-80] and show also that the loss of these subunits affects the elongation reaction.

scholarly journals Studies on the inhibition by α-amanitin of single-step addition reactions and productive RNA synthesis catalysed by wheat-germ RNA polymerase II

1989 ◽  
Vol 258 (1) ◽  
pp. 165-169 ◽  
Author(s):  
L de Mercoyrol ◽  
C Job ◽  
D Job
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Wheat Germ ◽  
Rna Synthesis ◽  
Single Step ◽  
Chain Elongation ◽  
Higher Plant ◽  
Experimental Conditions ◽  
Phosphodiester Bond ◽  
Alpha Amanitin

The rate of formation of a single phosphodiester bond with UTP substrate, U-A primer, poly[d(A-T)] template and wheat-germ RNA polymerase II is greatly depressed in the presence of alpha-amanitin. Half-maximal inhibition occurs at 0.04 microgram/ml, in close agreement with published values for inhibition of productive RNA synthesis with class II RNA polymerases from higher-plant species. However, a sizeable proportion of U-A-U synthesis is resistant to inhibition by excess alpha-amanitin. In the additional presence of ATP, i.e. under experimental conditions permitting RNA chain elongation, the synthesis of poly[r(A-U)] is arrested after the formation of the first phosphodiester bond. The results support the contention that the main enzymic process disrupted by alpha-amanitin is the translocation step of the transcription complex along the DNA template.

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