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.

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 Multi-step resistance to Chloramphenicol in RC-stringent Escherichia coli K12—its effect on the induction of RNA synthesis by antibiotics under amino acid starvation

1965 ◽  
Vol 6 (2) ◽  
pp. 304-309 ◽  
Author(s):  
E. C. R. Reeve ◽  
J. O. Bishop
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Resistant Strain ◽  
Parent Strain ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Sensitive Strain ◽  
Escherichia Coli K12 ◽  
High Doses

A multi-step Chloramphenicol (CM)-resistant derivative of an RC-stringent strain of Escherichia coli auxotrophic for threonine and leucine was resistant also to Aureomycin (AM) and Puromycin (PM). All three antibiotics released the repression of RNA synthesis due to amino acid starvation in the CM-sensitive parent strain, their relative activities being about 1:10:100 for AM: CM: PM. High doses of AM and CM failed to induce RNA synthesis. The CM-resistant strain required greater concentrations of each antibiotic than the sensitive strain to induce the same level of RNA synthesis, and appeared to be about one hundred times, ten times and five times more resistant to CM, AM and PM, respectively, than the sensitive strain.

RNA synthesis in T4 infected Escherichia coli during amino acid starvation

Virology ◽  
1972 ◽  
Vol 50 (1) ◽  
pp. 273-276 ◽  
Author(s):  
Pierluigi Donini ◽  
Gordon Edlin
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Synthesis ◽  
Amino Acid Starvation

scholarly journals Nucleic acid synthesis and nucleotide pools in purine-deficient Escherichia coli

1970 ◽  
Vol 120 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Gillian A. Thomas ◽  
N. F. Varney ◽  
K. Burton
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Rna Synthesis ◽  
Adenine Nucleotides ◽  
Acid Synthesis ◽  
Purine Nucleotides ◽  
Low Concentration ◽  
Intracellular Atp ◽  
Nucleotide Pools

1. The synthesis of nucleic acids and the content of purine nucleotides have been studied in selected purine-requiring strains of Escherichia coli including a purB− strain and a purB−guaA− strain. 2. When the exogenous purines can be converted into GTP but not into ATP, RNA is synthesized at the expense of intracellular ATP, ADP and AMP. 3. Net synthesis of RNA as measured by the incorporation of uracil can be correlated with the availability of GTP except when ATP falls to a very low concentration. 4. Nicotinamide nucleotides are not an important reservoir of adenine nucleotides for RNA synthesis.

Relationship between ppGpp levels and rates of protein and RNA synthesis in Escherichia coli

1976 ◽  
Vol 54 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Gillian Chaloner-Larsson ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Inverse Relationship ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Cellular Proteins ◽  
Mrna Species ◽  
Protein And Rna Synthesis ◽  
Rna And Protein Synthesis

When amino acid starvation is ended in stringent (relA+) strains of Escherichia coli, the rates of RNA and protein synthesis as well as their accumulation return to normal more slowly in spoT− strains than in the spoT+ strains. The level of ppGpp accumulated declines more slowly in the spoT− strains than in the spoT+ strains. Thus, there is an inverse relationship between ppGpp levels and the rates of RNA and protein synthesis. The slow resumption of protein synthesis in the spoT−relA+ strains could therefore be explained in terms of the limited synthesis of mRNA species coding for the bulk of cellular proteins.

Effects of the spoT and relA Mutation on the Synthesis and Accumulation of ppGpp and RNA during Glucose Starvation

1978 ◽  
Vol 56 (4) ◽  
pp. 264-272 ◽  
Author(s):  
Gillian Chaloner-Larsson ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Protein Accumulation ◽  
Glucose Starvation ◽  
Basal Rate ◽  
Synthetic Rate ◽  
K 12 ◽  
Stimulation Of

The effects of glucose starvation on the accumulation and synthesis of guanosine 3′,5′-bis(diphosphate) (ppGpp) were compared in four Escherichia coli K-12 strains having four different combinations of the spoT and relA alleles: spoT+relA+, spoT relA+, spoT+relA, and spoT relA. Glucose starvation caused a rapid and complete inhibition of RNA and protein accumulation and severe inhibition of RNA synthesis in all four strains. However, ppGpp accumulated only gradually in the relaxed (relA) strains and rapidly in the stringent (relA+) strains. Thus, ppGpp accumulation is not obligatory to the inhibition of RNA synthesis and accumulation during glucose starvation. During growth, relA strains synthesized ppGpp at a rate comparable with that in their relA+ partners. Glucose starvation did not affect the basal rate of ppGpp synthesis in the relA strains, but caused a transient stimulation of ppGpp synthesis in the relA+ strains. This suggests that glucose starvation causes transient amino-acid starvation. Since ppGpp accumulated in the relA strain without a change in its synthetic rate, it is inferred that ppGpp degradation decreased during glucose starvation. During growth, the turnover of ppGpp was considerably slower in the spoT strains than in the spoT+ strains. This suggests that the slower degradation of ppGpp in the spoT strains is counterbalanced by the slower synthesis of ppGpp. This difference in the rate of ppGpp synthesis became apparent when the relA strains were starved for glucose: The spoT relA strain accumulated ppGpp more slowly than did the spoT+relA strain.

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