Partenaires

CNRS


Rechercher


Accueil > Publications > Recherche par années > Années 1990 > 1993

Oconnor, TR ; Graves, RJ ; Demurcia, G ; Castaing, B ; Laval, J

FPG protein of escherichia-coli is a zinc finger protein whose cysteine residues have a structural and or functional-role

Journal of Biological Chemistry 268 (12) 9063-9070

par Administrateur - publié le

Abstract :

The Fpg protein of Escherichia coli is a DNA repair enzyme with DNA glycosylase, abasic site nicking, and deoxyribose excising activities. Analysis of the amino acid sequence of this protein suggests that the Fpg protein is a zinc finger protein with a Cys-X2-Cys-X16-Cys-X2-Cys motif. Competition experiments show that the Fpg protein substitutes Cu(II), Cd(II), and Hg(II), metal ions classically associated with substitutions in zinc finger proteins. The Fpg protein activities are inhibited following the reaction with a Cys-specific reagent at low protein:reagent ratios, suggesting that these residues are important for the enzymatic activities. Site-directed mutagenesis was used to produce 6 mutant Fpg proteins with Cys —> Gly mutations.