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

Castaing, B ; Geiger, A ; Seliger, H ; Nehls, P ; Laval, J ; Zelwer, C ; Boiteux, S

Cleavage and binding of a DNA fragment containing a single 8-oxoguanine by wild-type and mutant fpg proteins

Nucleic Acids Research 21 (12) 2899-2905

par Administrateur - publié le

Abstract :

A 34-mer oligonucleotide containing a single 7,8-dihydro-8-oxoguanine (8-OxoG) residue was used to study the enzymatic and DNA binding properties of the Fpg protein from E.coli. The highest rates of incision of the 8-OxoG containing strand by the Fpg protein were observed for duplexes where 8-OxoG was opposite C (*G/C) or T (*G/T). In contrast, the rates of incision of duplexes containing 8-OxoG opposite G (*G/G) and A (*G/A) were 5-fold and 200-fold slower. Gel retardation studies showed that the Fpg protein had a strong affinity for duplexes where the 8-OxoG was opposite pyrimidines and less affinity for duplexes where the 8-OxoG was opposite purines. K(D)app values were 0.6 nM (*G/C), 1.0 nM (*G/T), 6.0 nM (*G/G) and 16.0 nM (*G/A).