recA +-dependent inactivation of the lambda repressor in Escherichia coli lysogens by γ-radiation and by tif expression

1975 ◽  
Vol 141 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Stephen C. West ◽  
Keith A. Powell ◽  
Peter T. Emmerson
Keyword(s):  
Escherichia Coli ◽  
Lambda Repressor ◽  
Γ Radiation ◽  
Dependent Inactivation

scholarly journals exrB: amalB-linked gene inEscherichia coliB involved in sensitivity to radiation and filament formation

1974 ◽  
Vol 23 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Joseph Greenberg ◽  
Leonard J. Berends ◽  
John Donch ◽  
Michael H. L. Green
Keyword(s):  
Escherichia Coli ◽  
Normal Growth ◽  
Filament Formation ◽  
Wild Type ◽  
Sensitive Mutant ◽  
Γ Radiation ◽  
Linked Gene ◽  
Derivatives Of

SUMMARYPAM 26, a radiation-sensitive mutant ofEscherichia colistrain B, is described. Its properties are attributable to a mutation in a gene,exrB, which is cotransducible withmalB. It differs fromuvrA(alsomalB-linked) derivatives of strain B in being sensitive to 1-methyl-3-nitro-1-nitroso-guanidine and γ-radiation, and in being able to reactivate UV-irradiated phage T3. It differs fromexrA(alsomalB-linked) derivatives of strain B in forming filaments during the course of normal growth as well as after irradiation. WhenexrBwas transduced into a K12 (lon+) strain, filaments did not form spontaneously. Three-point transductions established the order of markers asmet A malB exrB. Based on an analysis of the frequency of wild-type recombinants in a reciprocal transduction betweenexrAandexrBstrains, it was inferred that they are not isogenic and that the order of markers ismalB exrA exrB.

scholarly journals Incorporation of 5-substituted uracil derivatives into nucleic acids. The isolation and γ-radiation-sensitivity of bacteriophage T3 containing the thymine analogue 5-vinyluracil

1980 ◽  
Vol 187 (1) ◽  
pp. 257-260 ◽  
Author(s):  
E T J Chelton ◽  
M Duggan ◽  
R N Hunston ◽  
A S Jones ◽  
M K O'Leary ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acids ◽  
Gamma Radiation ◽  
Radiation Sensitivity ◽  
Γ Radiation ◽  
Uracil Derivatives ◽  
Phage Dna

Bacteriophage T3 was produced in a form that contained 32% of its normal DNA thymine residues replaced with 5-vinyluracil residues by infecting a thymine-requiring strain of Escherichia coli with phage T3 in a medium containing 5-vinyluracil. When 2′-deoxy-5-vinyluridine was added to the medium instead, no incorporation was observed into the phage DNA, and the presence of the deoxyribonucleoside severely decreased the number of viable phage particles produced. The analogue-containing phage, although initially viable, rapidly lost viability when stored, but it was no more sensitive than was normal phage T3 to the effect of gamma-radiation.

Synthesis of 5-fluoro-β-D-glucopyranosyluronic acid fluoride and its evaluation as a mechanistic probe of Escherichia coli β-glucuronidase

2001 ◽  
Vol 79 (5-6) ◽  
pp. 510-518 ◽  
Author(s):  
Alexander W Wong ◽  
Shouming He ◽  
Stephen G Withers
Keyword(s):  
Escherichia Coli ◽  
Triple Quadrupole Mass Spectrometer ◽  
Acid Fluoride ◽  
Radical Bromination ◽  
Dependent Inactivation ◽  
Phenacyl Ester ◽  
Peptic Digestion ◽  
Good Potential ◽  
Mechanistic Probe ◽  
Enzyme Intermediate

Synthesis of the potential mechanism-based inactivator of β-D-glucuronidases (5-fluoro-β-D-glucopyranosyluronic acid fluoride) was accomplished via a six-step process from D-glucuronic acid that involved radical bromination at C-5 and displacement of the bromide by fluoride. A key step in this process was the masking of the carboxylic acid as a phenacyl ester. This group is uniquely stable to conditions of photobromination and fluoride displacement, yet removable under very mild conditions. Incubation of the Escherichia coli β-glucuronidase with 5-fluoro-β-D-glucopyranosyluronic acid fluoride resulted in time-dependent inactivation of the enzyme through the accumulation of a covalent 5-fluoro-α-D-glucopyranosyluronic acid-enzyme. Peptic digestion of the 5-fluoro-α-D-glucopyranosyluronic acid-enzyme intermediate and subsequent analysis by liquid chromatography coupled to an electrospray ionization triple quadrupole mass spectrometer indicated the presence of a 5-fluoro-α-D-glucopyranosyluronic acid-modified peptide. This peptide was partially purified by HPLC and its sequence determined by tandem mass spectrometry in the daughter ion scan mode, permitting the identification of Glu504 as the catalytic nucleophile within the sequence ITEYGVD. This new reagent is therefore useful for the specific, mechanism-based inactivation of glycuronidases and has good potential in other studies of enzymes of this general class.Key words: β-glucuronidase, catalytic nucleophile, 5-fluoro-β-D-glucopyranosyluronic acid fluoride, electrospray MS.

Overproduction of the RecD polypeptide sensitizes Escherichia coli cells to γ-radiation

1992 ◽  
Vol 281 (2) ◽  
pp. 123-127 ◽  
Author(s):  
Krunoslav Brčić-Kostić ◽  
Igor Stojiljković ◽  
Erika Salaj-Šmic ◽  
Željko Trgovčević
Keyword(s):  
Escherichia Coli ◽  
Γ Radiation ◽  
Escherichia Coli Cells

scholarly journals Expression in Escherichia coli, purification and characterization of two mammalian thioesterases involved in fatty acid synthesis

1991 ◽  
Vol 273 (3) ◽  
pp. 787-790 ◽  
Author(s):  
J Naggert ◽  
A Witkowski ◽  
B Wessa ◽  
S Smith
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Acid Synthesis ◽  
Temperature Sensitive ◽  
Lambda Repressor ◽  
Thioesterase Ii ◽  
Chain Lengths

Thioesterase I, a constituent domain of the multifunctional fatty acid synthase, and thioesterase II, an independent monofunctional protein, catalyse the chain-terminating reaction in fatty acid synthesis de novo at long and medium chain lengths respectively. The enzymes have been cloned and expressed in Escherichia coli under the control of the temperature-sensitive lambda repressor. The recombinant proteins are full-length catalytically competent thioesterases with specificities indistinguishable from those of the natural enzymes.

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