ADENINE NUCLEOTIDE BREAKDOWN AND ITS RELATIONSHIP TO POLYNUCLEOTIDE PHOSPHORYLASE IN THE CROWN-GALL TUMOR INDUCING ORGANISM AGROBACTERIUM TUMEFACIENS

1961 ◽  
Vol 39 (4) ◽  
pp. 773-785 ◽  
Author(s):  
A. Vardanis ◽  
R. M. Hochster
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Adenylate Kinase ◽  
Crown Gall ◽  
Adenine Nucleotide ◽  
Moderate Activity ◽  
Unusual Property ◽  
Polynucleotide Phosphorylase ◽  
Phosphodiesterase Activity ◽  
Crown Gall Tumor

Cell-free extracts of the crown-gall tumor inducing organism Agrobacterium tumefaciens (strain B6) have been shown to convert ATP to ADP relatively slowly. An adenylate kinase of only moderate activity has been found.Crude extracts of this organism contain an extremely active polynucleotide phosphorylase which rapidly catalyzes the synthesis of polyadenylate from ADP, releasing Piin stoichiometric proportions. Extracts are also shown to exhibit some phosphodiesterase activity towards the polyadenylate so formed.Even though the enzymatic conversions of adenosine and of IMP to hypoxanthine are shown to occur readily it has not been possible to demonstrate any metabolic link between AMP and either adenosine or IMP. Extracts of A. tumefaciens have the unusual property of being unable to metabolize further AMP or other similar mononucleotides (with the exception of IMP).It is shown also that polynucleotide phosphorylase is active not only in extracts of crown-gall tumor inducing organisms but also in those of at least one related non-tumorogenic species of Agrobacterium.

ON THE NUCLEOTIDE SPECIFICITY OF THE POLYNUCLEOTIDE PHOSPHORYLASE OF THE CROWN-GALL TUMOR-INDUCING ORGANISM AGROBACTERIUM TUMEFACIENS

1961 ◽  
Vol 39 (11) ◽  
pp. 1695-1704 ◽  
Author(s):  
A. Vardanis ◽  
R. M. Hochster
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Crown Gall ◽  
Rna Synthesis ◽  
The Other ◽  
Moderate Activity ◽  
Polynucleotide Phosphorylase ◽  
Crown Gall Tumor ◽  
Nucleotide Specificity

An investigation of the nucleotide specificity of the polynucleotide phosphorylase of Agrobacterium tumefaciens was undertaken, using the measurable increase in viscosity as an index of activity. It was found that ADP and CDP were polymerized readily and at approximately equal rates. The enzyme exhibited more moderate activity with UDP and was completely inactive with GDP. The ineffectiveness of the enzyme with mixtures of all four ribonucleoside diphosphates was traced to the ability of GDP to act as an inhibitor in the polymerization of the other diphosphates. Evidence is presented to show that the inhibition of poly A synthesis effected by GDP is competitive. On the basis of the results obtained it is concluded that the polynucleotide phosphorylase is not likely to be responsible for RNA synthesis in A. tumefaciens.

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.

Polymyxin resistance in Agrobacterium tumefaciens and its effect on crown gall tumor induction

1979 ◽  
Vol 25 (2) ◽  
pp. 185-191 ◽  
Author(s):  
C. H. Liao ◽  
G. T. Heberlein
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Crown Gall ◽  
Host Plants ◽  
Polymyxin B ◽  
Defined Medium ◽  
Tumor Initiation ◽  
Tumor Induction ◽  
Crown Gall Tumor ◽  
Pinto Bean ◽  
Cell Envelopes

Polymyxin-resistant (PBLr) mutants of Agrobacterium tumefaciens A6, B6, and B6M were isolated from polymyxin-sensitive (PBLs) parent strains in a defined medium containing 600 μg of polymyxin B sulfate per millilitre. The weight and number of tumors induced by PBLr mutants on a variety of host plants such as carrot, potato, and pinto bean were 45–75% less than those induced by PBLs wild types. The crude cell envelopes (CCE) prepared from both PBLs and PBLr bacteria were inhibitory for tumor initiation when they were applied before or during the inoculation of viable tumorigenic bacteria, but not when they were applied 30 min after the inoculation of infectious bacteria. The potency to inhibit the tumor initiation by the CCE prepared from PBLs cells was approximately 50% higher than that by the equal amount of the CCE prepared from PBLr cells. The concentration of CCE preparations required to reduce tumor induction 50% in carrot and pinto bean was determined to be 2.6 mg/mL and 4.0–6.2 mg/mL for the CCE derived from PBLs and PBLr cells, respectively. These data suggest that the envelope structure or composition of PBLs and PBLr cells is distinct, and that the acquisition of resistance to polymyxin by agrobacteria modifies envelope structure or components which are essential for tumor initiation.

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