scholarly journals The reaction catalysed by a partially purified nucleoside triphosphate-dependent deoxyribonucleic acid-breakdown system from Mycobacterium smegmatis

1969 ◽  
Vol 115 (3) ◽  
pp. 6P-7P ◽  
Author(s):  
F G Winder ◽  
M Lavin
Keyword(s):  
Mycobacterium Smegmatis ◽  
Deoxyribonucleic Acid ◽  
Nucleoside Triphosphate

scholarly journals A nucleoside triphosphate-dependent deoxyribonucleic acid-breakdown system in Mycobacterium smegmatis, and the effect of iron limitation on the activity of this system

1969 ◽  
Vol 111 (5) ◽  
pp. 679-687 ◽  
Author(s):  
F. G. Winder ◽  
M. P. Coughlan
Keyword(s):  
Dna Content ◽  
Mycobacterium Smegmatis ◽  
Deoxyribonucleic Acid ◽  
Maximal Activity ◽  
Enzyme Concentration ◽  
Iron Limitation ◽  
Nucleoside Triphosphate ◽  
Primary Products ◽  
Rate Of Reaction ◽  
Optimum Ph

1. The presence of a nucleoside triphosphate-dependent DNA-breakdown system was demonstrated in extracts of Mycobacterium smegmatis. Its activity was increased substantially by iron limitation, apparently after the fall in DNA content that took place under these conditions. A maximal activity of about 0·2μmole of deoxyribonucleotide/30min./mg. of protein was found in crude extracts. 2. After slight purification by streptomycin treatment, the enzyme showed maximal activity with undenatured DNA (Km≃200μg./ml.), ATP (Km≃1·2mm) or UTP, CTP and GTP giving lower activity and pyrophosphate giving none, and Mg2+ ions (optimum concn. 12mm). The optimum pH was 8·5. 3. In the assay system there was proportionality between enzyme concentration and rate of reaction, but the rate fell off with time. 4. ATP was broken down in the reaction and monodeoxy-ribonucleotides were among the products, but the presence of some oligodeoxy-ribonucleotides was not excluded and the degree of phosphorylation of the primary products was uncertain.

scholarly journals Nucleic acid enzymology of extremely halophilic bacteria. Halobacterium cutirubrum deoxyribonucleic acid-dependent ribonucleic acid polymerase

1971 ◽  
Vol 121 (4) ◽  
pp. 621-627 ◽  
Author(s):  
B. Gregory Louis ◽  
P. S. Fitt
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Rna Polymerase ◽  
Deoxyribonucleic Acid ◽  
Halophilic Bacteria ◽  
Nucleoside Triphosphate ◽  
Extreme Halophile ◽  
Univalent Cations ◽  
Absolute Requirement ◽  
Nucleoside Triphosphates

1. DNA-dependent RNA polymerase was purified 150-fold from crude extracts of the extreme halophile Halobacterium cutirubrum. 2. The enzyme requires the presence of native DNA and all four nucleoside triphosphates to incorporate 14C-labelled nucleoside triphosphate into an acid-insoluble ribonuclease-sensitive product. 3. It has an absolute requirement for both Mn2+ and Mg2+. 4. The polymerase requires a high salt concentration for stability, but is markedly inhibited by univalent cations. 5. Its molecular weight is very low compared with that of Escherichia coli RNA polymerase.

DEOXYRIBONUCLEIC ACID DEPENDENT RIBONUCLEIC ACID SYNTHESIS IN THE CROWN-GALL TUMOR-INDUCING ORGANISM AGROBACTERIUM TUMEFACIENS

1963 ◽  
Vol 41 (7) ◽  
pp. 1503-1518 ◽  
Author(s):  
R. M. Hochster ◽  
V. M. Chang
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Crown Gall ◽  
Messenger Rna ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Nucleoside Triphosphate ◽  
Satisfactory Explanation ◽  
Crown Gall Tumor ◽  
Other Information ◽  
Hydrolysis Of

The enzyme RNA polymerase has been partially purified from cell-free extracts of the crown-gall tumor-inducing organism Agrobacterium tumefaciens. The four triphosphates ATP, CTP, GTP, and UTP, manganese (or magnesium) ions, and DNA are all required for activity. DNA acts as a template in the formation of the new RNA molecule the base composition of which exactly mimics that of the particular DNA used. The dependence of the reaction on time, pH, and on the concentrations of nucleoside triphosphate, DNA, and protein has been worked out. The exact requirements of the entire system are delineated, the effect of physical alteration of the DNA used (heating, cooling, sonic oscillation) has been examined and a new observation made on the stimulation of DNA action by 1-minute sonic pretreatment.Actinomycin D is shown to inhibit the reaction completely at 2.8 × 10−5 M while atabrine, a new inhibitor, requires a concentration of 3.3 × 10−3 M under the conditions specified. Hydrolysis of the reaction product by means of a variety of procedures and other information obtained show that the reaction product is, indeed, RNA.The data reported herein are regarded as providing a satisfactory explanation for the mechanism of biosynthesis of at least one type of RNA (presumably "messenger" RNA) in A. tumefaciens.

DEOXYRIBONUCLEIC ACID DEPENDENT RIBONUCLEIC ACID SYNTHESIS IN THE CROWN-GALL TUMOR-INDUCING ORGANISM AGROBACTERIUM TUMEFACIENS

1963 ◽  
Vol 41 (1) ◽  
pp. 1503-1518 ◽  
Author(s):  
R. M. Hochster ◽  
V. M. Chang
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Crown Gall ◽  
Messenger Rna ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Nucleoside Triphosphate ◽  
Satisfactory Explanation ◽  
Crown Gall Tumor ◽  
Other Information ◽  
Hydrolysis Of

The enzyme RNA polymerase has been partially purified from cell-free extracts of the crown-gall tumor-inducing organism Agrobacterium tumefaciens. The four triphosphates ATP, CTP, GTP, and UTP, manganese (or magnesium) ions, and DNA are all required for activity. DNA acts as a template in the formation of the new RNA molecule the base composition of which exactly mimics that of the particular DNA used. The dependence of the reaction on time, pH, and on the concentrations of nucleoside triphosphate, DNA, and protein has been worked out. The exact requirements of the entire system are delineated, the effect of physical alteration of the DNA used (heating, cooling, sonic oscillation) has been examined and a new observation made on the stimulation of DNA action by 1-minute sonic pretreatment.Actinomycin D is shown to inhibit the reaction completely at 2.8 × 10−5 M while atabrine, a new inhibitor, requires a concentration of 3.3 × 10−3 M under the conditions specified. Hydrolysis of the reaction product by means of a variety of procedures and other information obtained show that the reaction product is, indeed, RNA.The data reported herein are regarded as providing a satisfactory explanation for the mechanism of biosynthesis of at least one type of RNA (presumably "messenger" RNA) in A. tumefaciens.

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