Endonuclease VII of phage T4 nicks N-2-acetylaminofluorene-induced DNA structures in vitro.
We have tested in vitro the activity of T4 endonuclease VII on three different double-stranded oligonucleotides bearing a single N-2-acetylaminofluorene (AAF) adduct covalently bound to each of the three guanine residues located within the NarI site (G1G2CG3CC), a strong frameshift mutation hot spot in E. coli. With the oligonucleotides modified at G2 and G3 a specific cleavage pattern with T4 endonuclease VII was observed in the complementary strand while no cleavage was found in the adduct-bearing strand. On the other hand, when G1 was modified, only a very faint cleavage band was observed (< 1%). These differences in nicking among the three AAF-modified DNA substrates are discussed in terms of the polymorphic nature in adduct-induced DNA structures as previously shown. This "non-physiological" activity of a DNA resolvase is discussed in terms of a potential role for such enzymes in the induction of frameshift mutations.
Bertrand-Burggraf
E
E
UPR 9003 de Cancérogenèse et de Mutagenèse Moléculaire et Structurale, Institut de Biologie Moléculaire et Cellulaire du Centre National de la Recherche Scientifique, Strasbourg, France.
Kemper
B
B
Fuchs
R P
RP
D015073:2-Acetylaminofluorene / Q000378:metabolism* / Q000494:pharmacology; D017122:Bacteriophage T4 / Q000201:enzymology; D001483:Base Sequence; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D016368:Frameshift Mutation / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000378:metabolism
D009838:Oligodeoxyribonucleotides; D004247:DNA; D015073:2-Acetylaminofluorene; D004706:Endodeoxyribonucleases; C035571:endodeoxyribonuclease VII