Repair of N-methyl-N'-nitro-N-nitrosoguanidine-induced DNA damage by ABC excinuclease.

Abstract

Escherichia coli has several overlapping DNA repair pathways which act in concert to eliminate the DNA damage caused by a diverse array of physical and chemical agents. The ABC excinuclease which is encoded by the uvrA, uvrB, and uvrC genes mediates both the incision and excision steps of nucleotide excision repair. Traditionally, this repair pathway has been assumed to be active against DNA adducts that cause major helical distortions. To determine the level of helical deformity required for recognition and repair by ABC excinuclease, we have evaluated the substrate specificity of this enzyme by using DNA damaged by N-methyl-N'-nitro-N-nitrosoguanidine. ABC excinuclease incised methylated DNA in vitro in a dose-dependent manner in a reaction that was ATP dependent and specific for the fully reconstituted enzyme. In vivo studies with various alkylation repair-deficient mutants indicated that the excinuclease participated in the repair of DNA damage induced by N-methyl-N'-nitro-N-nitrosoguanidine.

• Authors: B Van Houten, A Sancar
• Journal: Journal of bacteriology (J Bacteriol) Vol. 169 Issue 2 Pg. 540-5 (Feb 1987) ISSN: 0021-9193 [Print] United States
• PMID: 3542961 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Escherichia coli Proteins
• Methylnitronitrosoguanidine
• Endodeoxyribonucleases
• endodeoxyribonuclease uvrABC

Topics

• DNA Damage
• DNA Repair
• Dose-Response Relationship, Drug
• Endodeoxyribonucleases (metabolism)
• Escherichia coli (drug effects, enzymology, genetics)
• Escherichia coli Proteins
• Genotype
• Kinetics
• Methylnitronitrosoguanidine (pharmacology)
• Mutation
• Species Specificity