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Wyszukujesz frazę "Nowosielska, Anetta" wg kryterium: Autor


Wyświetlanie 1-3 z 3
Tytuł:
Reversion of argE3 ochre strain Escherichia coli AB1157 as a tool for studying the stationary-phase (adaptive) mutations.
Autorzy:
Nowosielska, Anetta
Grzesiuk, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/1044376.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mutY
replica plating
Arg+ revertants
Escherichia coli
adaptive mutations
mutT
Opis:
Adaptive (starvation-associated) mutations occur in non-dividing cells and allow growth under the selective conditions imposed. We developed a new method for the determination of adaptive mutations in Escherichia coli. The system involves reversion to prototrophy of the argE3OC mutation and was tested on AB1157 strains mutated in the mutT and/or mutY genes. The bacteria that mutated adaptively grow into colonies on minimal medium plates devoid of arginine (starvation conditions) when incubated longer than 4 days. Using the replica plating method we solved the problem of discrimination between growth-dependent and adaptive argE3→Arg+ revertants. Phenotype analysis and susceptibility of the Arg+ revertants to a set of T4 phage mutants create an additional possibility to draw a distinction between these two types of Arg+ revertants.
Źródło:
Acta Biochimica Polonica; 2000, 47, 2; 459-467
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spontaneous mutagenesis in exponentially growing and stationary-phase, umuDC-proficient and -deficient, Escherichia coli dnaQ49.
Autorzy:
Nowosielska, Anetta
Nieminuszczy, Jadwiga
Grzesiuk, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/1041546.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
dnaQ49
argE3→Arg+ revertants
E. coli
Pol V
spontaneous mutagenesis
stationary-phase mutations
Opis:
Spontaneous mutations arise not only in exponentially growing bacteria but also in non-dividing or slowly dividing stationary-phase cells. In the latter case mutations are called adaptive or stationary-phase mutations. High spontaneous mutability has been observed in temperature sensitive Escherichia coli dnaQ49 strain deficient in 3'→5' proofreading activity assured by the ε subunit of the main replicative polymerase, Pol III. The aim of this study was to evaluate the effects of the dnaQ49 mutation and deletion of the umuDC operon encoding polymerase V (Pol V) on spontaneous mutagenesis in growing and stationary-phase E. coli cells. Using the argE3OC →Arg+ reversion system in the AB1157 strain, we found that the level of growth-dependent and stationary-phase Arg+ revertants was significantly increased in the dnaQ49 mutant at the non-permissive temperature of 37°C. At this temperature, in contrast to cultures grown at 28°C, SOS functions were dramatically increased. Deletion of the umuDC operon in the dnaQ49 strain led to a 10-fold decrease in the level of Arg+ revertants in cultures grown at 37°C and only to a 2-fold decrease in cultures grown at 28°C. Furthermore, in stationary-phase cultures Pol V influenced spontaneous mutagenesis to a much lesser extent than in growing cultures. Our results indicate that the level of Pol III desintegration, dependent on the temperature of incubation, is more critical for spontaneous mutagenesis in stationary-phase dnaQ49 cells than the presence or absence of Pol V.
Źródło:
Acta Biochimica Polonica; 2004, 51, 3; 683-692
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of SOS-induced Pol II, Pol IV, and Pol V DNA polymerases on UV-induced mutagenesis and MFD repair in Escherichia coli cells.
Autorzy:
Wrzesiński, Michał
Nowosielska, Anetta
Nieminuszczy, Jadwiga
Grzesiuk, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/1041471.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
MFD
polB
UV induced mutagenesis
E. coli
dinB
mutD5
umuDC
Opis:
Irradiation of organisms with UV light produces genotoxic and mutagenic lesions in DNA. Replication through these lesions (translesion DNA synthesis, TSL) in Escherichia coli requires polymerase V (Pol V) and polymerase III (Pol III) holoenzyme. However, some evidence indicates that in the absence of Pol V, and with Pol III inactivated in its proofreading activity by the mutD5 mutation, efficient TSL takes place. The aim of this work was to estimate the involvement of SOS-inducible DNA polymerases, Pol II, Pol IV and Pol V, in UV mutagenesis and in mutation frequency decline (MFD), a mechanism of repair of UV-induced damage to DNA under conditions of arrested protein synthesis. Using the argE3→Arg+ reversion to prototrophy system in E. coli AB1157, we found that the umuDC-encoded Pol V is the only SOS-inducible polymerase required for UV mutagenesis, since in its absence the level of Arg+ revertants is extremely low and independent of Pol II and/or Pol IV. The low level of UV-induced Arg+ revertants observed in the AB1157mutD5ΔumuDC strain indicates that under conditions of disturbed proofreading activity of Pol III and lack of Pol V, UV-induced lesions are bypassed without inducing mutations. The presented results also indicate that Pol V may provide substrates for MFD repair; moreover, we suggest that only those DNA lesions which result from umuDC-directed UV mutagenesis are subject to MFD repair.
Źródło:
Acta Biochimica Polonica; 2005, 52, 1; 139-147
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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