Radiation-induced oxidative damage to the DNA-binding domain of the lactose repressor.

ABSTRACT: Understanding the cellular effects of radiation-induced oxidation requires the unravelling of key molecular events, particularly damage to proteins with important cellular functions. The Escherichia coli lactose operon is a classical model of gene regulation systems. Its functional mechanism involves the specific binding of a protein, the repressor, to a specific DNA sequence, the operator. We have shown previously that upon irradiation with gamma-rays in solution, the repressor loses its ability to bind the operator. Water radiolysis generates hydroxyl radicals (OH* radicals) which attack the protein. Damage of the repressor DNA-binding domain, called the headpiece, is most likely to be responsible of this loss of function. Using CD, fluorescence spectroscopy and a combination of proteoly

SUBMITTER: Gillard N 

PROVIDER: S-EPMC1876370 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature