Escherichia coli endonuclease III is not an endonuclease but a β-elimination catalyst
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چکیده
منابع مشابه
Endonuclease III (nth) mutants of Escherichia coli.
Two strains that overproduce endonuclease III were found in a colony bank containing hybrid ColE1-Escherichia coli plasmids. The enzyme was identified in crude extracts by the degradation of partially depyrimidinated DNA in the presence of EDTA, by its sedimentation velocity, and by its associated thymine glycol-DNA glycosylase activity. An insertion mutation was produced by cloning the kanamyc...
متن کاملEndonuclease II of Escherichia coli is exonuclease III.
Exonuclease III, a phosphatase-exonuclease specific for bihelical DNA, wn the preparation was endonuclease II, an activity specific for DNA that has been partially depurinated by treatment with methyl methanesulfonate. The two activities, which could not be separated by electrophoresis, by sedimentation, or by gel filtration, were associated with a single monomeric protein of 28,000 daltons. To...
متن کاملSpontaneous and osmium tetroxide-induced mutagenesis in an Escherichia coli strain deficient in both endonuclease III and endonuclease VIII.
Thymine glycol, uracil glycol, 5-hydroxycytosine and 5-hydroxyuracil are common base lesions produced by cellular metabolism as well as ionizing radiation and environmental carcinogens. Escherichia coli DNA glycosylase, endonuclease III and endonuclease VIII recognize and remove these lesions from DNA. In this study, we assessed the mutagenic potential of these lesions in the supF gene as a for...
متن کاملCharacterization of Escherichia coli endonuclease VIII.
Escherichia coli endonuclease VIII (endo VIII) was identified as an enzyme that, like endonuclease III (endo III), removes radiolysis products of thymine including thymine glycol, dihydrothymine, beta-ureidoisobutyric acid, and urea from double-stranded plasmid or phage DNA and cleaves the DNA strand at abasic (AP) sites (Melamede, R. J., Hatahet, Z., Kow, Y. W., Ide., H., and Wallace, S. S. (1...
متن کاملThe genes encoding endonuclease VIII and endonuclease III in Escherichia coli are transcribed as the terminal genes in operons.
Escherichia coli endonuclease VIII and endo-nuclease III are oxidative base excision repair DNA glycosylases that remove oxidized pyrimidines from DNA. The genes encoding these proteins, nei and nth, are both co-transcribed as the terminal genes in operons. nei is the terminal gene in an operon with four open reading frames that encode proteins of unknown function. This operon has two confirmed...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1987
ISSN: 0264-6021,1470-8728
DOI: 10.1042/bj2420565