Henia Shwartz

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Exposure of Escherichia coli to UV irradiation or nalidixic acid, which induce both the SOS and heat shock responses, led to a 3-4-fold increase in the amount of the beta subunit of DNA polymerase III holoenzyme, as assayed by Western blot analysis using anti-beta antibodies. Such an induction was observed also in a delta rpoH mutant lacking the heat(More)
In view of the potential biological importance of VIP, we have begun to examine the regulation of its biosynthesis. For this purpose we have, as a first step, searched for an enriched source of VIP biosynthesis. By a combination of chromatographic procedures and radioimmunoassays we discovered an as yet unknown source for VIP production, namely a human(More)
ABSTRACT The possibility of using local and imported warning systems for the management of fire blight (caused by the bacterium Erwinia amylovora) in pears was tested in Israel from 1997 to 2000. Three imported systems (MARYBLYT 4.3, BIS95, and Cougarblight 98C) and one local system (Fire Blight Control Advisory [FBCA]) were used. All systems were tested in(More)
ABSTRACT The coliform agar produced by Merck was tested for rapid diagnosis of Erwinia amylovora (the causal agent of fire blight) in pear blossoms. The medium enabled the diagnosis to be completed within 36 h. Diagnoses performed with the medium were confirmed by the BIOLOG and the fatty-acid profile methods. The diagnostic medium was used to determine the(More)
3,5,3' Triiodo-L-thyronine (T3) stimulated the uptake of 2-deoxy-D-glucose (2-DOG) into L6 cells, nongenomically, starting at subpicomolar concentrations and reaching a peak at concentrations of 1-10 nM. Stimulation at the peak was usually approximately 250%. The uptake of 2-DOG declined with higher concentrations of T(3). The dose-response curve of insulin(More)
Pear blossoms are the plant tissue that is most vulnerable to infection byErwinia amylovora (Burrill) Winslowet al., the causal agent of fire blight. The interacting effects of temperature, wetness duration and inoculum size on the development of fire blight symptoms in detached pear blossoms were determined in three sets of experiments conducted under(More)
A new mutagenesis assay system based on the phage lambda cro repressor gene residing on a plasmid was developed. The assay detects mutations in cro that decrease the binding of the repressor to the OR operator in an OR PR-lacZ fusion present in a lambda prophage. Mutations arose spontaneously during growth of E. coli cells harboring cro plasmids at a(More)
During in vitro replication of UV-irradiated single-stranded DNA with Escherichia coli DNA polymerase III holoenzyme termination frequently occurs at pyrimidine photodimers. The termination stage is dynamic and characterized by at least three different events: repeated dissociation-reinitiation cycles of the polymerase at the blocked termini; extensive(More)
The role of exonuclease activity in trans-lesion DNA replication with Escherichia coli DNA polymerase III holoenzyme was investigated. RecA protein inhibited the 3'----5' exonuclease activity of the polymerase 2-fold when assayed in the absence of replication and had no effect on turnover of dNTPs into dNMPs. In contrast, single-stranded DNA-binding(More)
The efficacy of oxolinic acid (at 200 and 300 μg a.i./l) and of several antibiotic compounds (streptomycin sulfate at 100 μg a.i./l, glycocide B at 700 μg a.i./l, kasugamycin at 80 μg a.i./l and gentamicin sulfate at 30 and 60 μg a.i./l) againstErwinia amylovora, the causal agent of fire blight in pears, was evaluated in 43 orchard experiments in 1997–2000(More)