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Effects of ionizing radiations on DNA-protein complexes; Effets des radiations ionisantes sur des complexes ADN-proteine

Abstract

The radio-induced destruction of DNA-protein complexes may have serious consequences for systems implicated in important cellular functions. The first system which has been studied is the lactose operon system, that regulates gene expression in Escherichia coli. First of all, the repressor-operator complex is destroyed after irradiation of the complex or of the protein alone. The damaging of the domain of repressor binding to DNA (headpiece) has been demonstrated and studied from the point of view of peptide chain integrity, conformation and amino acids damages. Secondly, dysfunctions of the in vitro induction of an irradiated repressor-unirradiated DNA complex have been observed. These perturbations, due to a decrease of the number of inducer binding sites, are correlated to the damaging of tryptophan residues. Moreover, the inducer protects the repressor when they are irradiated together, both by acting as a scavenger in the bulk, and by the masking of its binding site on the protein. The second studied system is formed by Fpg (for Formamido pyrimidine glycosylase), a DNA repair protein and a DNA with an oxidative lesion. The results show that irradiation disturbs the repair both by decreasing its efficiency of DNA lesion recognition and binding, and by altering its enzymatic activity.  More>>
Authors:
Publication Date:
Nov 15, 2005
Product Type:
Thesis/Dissertation
Report Number:
FRNC-TH-7085
Resource Relation:
Other Information: TH: These biologie et biophysique moleculaires et cellulaires; Also available from Service commun de la documentation de l'Universite d'Orleans. Section Sciences, 9, Rue de Saint-Amand, 45072 - Orleans Cedex 2 (France)
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS; BIOLOGICAL RADIATION EFFECTS; COMPLEXES; DNA; DNA DAMAGES; IONIZING RADIATIONS; PROTEINS; RADIOBIOLOGY; RADIOINDUCTION
OSTI ID:
21112686
Research Organizations:
Orleans Univ., 45 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR0800219120214
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
157 pages
Announcement Date:
Dec 19, 2008

Citation Formats

Gillard, N. Effects of ionizing radiations on DNA-protein complexes; Effets des radiations ionisantes sur des complexes ADN-proteine. France: N. p., 2005. Web.
Gillard, N. Effects of ionizing radiations on DNA-protein complexes; Effets des radiations ionisantes sur des complexes ADN-proteine. France.
Gillard, N. 2005. "Effects of ionizing radiations on DNA-protein complexes; Effets des radiations ionisantes sur des complexes ADN-proteine." France.
@misc{etde_21112686,
title = {Effects of ionizing radiations on DNA-protein complexes; Effets des radiations ionisantes sur des complexes ADN-proteine}
author = {Gillard, N}
abstractNote = {The radio-induced destruction of DNA-protein complexes may have serious consequences for systems implicated in important cellular functions. The first system which has been studied is the lactose operon system, that regulates gene expression in Escherichia coli. First of all, the repressor-operator complex is destroyed after irradiation of the complex or of the protein alone. The damaging of the domain of repressor binding to DNA (headpiece) has been demonstrated and studied from the point of view of peptide chain integrity, conformation and amino acids damages. Secondly, dysfunctions of the in vitro induction of an irradiated repressor-unirradiated DNA complex have been observed. These perturbations, due to a decrease of the number of inducer binding sites, are correlated to the damaging of tryptophan residues. Moreover, the inducer protects the repressor when they are irradiated together, both by acting as a scavenger in the bulk, and by the masking of its binding site on the protein. The second studied system is formed by Fpg (for Formamido pyrimidine glycosylase), a DNA repair protein and a DNA with an oxidative lesion. The results show that irradiation disturbs the repair both by decreasing its efficiency of DNA lesion recognition and binding, and by altering its enzymatic activity. (author)}
place = {France}
year = {2005}
month = {Nov}
}