Characterization of an 8-oxoguanine DNA glycosylase from Methanococcus jannaschii.
A thermostable 8-oxoguanine (oxoG) DNA glycosylase from Methanococcus jannaschii has been expressed in Escherichia coli, purified, and characterized. The enzyme, which has been named mjOgg, belongs to the same diverse DNA glycosylase superfamily as the 8-oxoguanine DNA glycosylases from yeast (yOgg1) and human (hOgg1) but is substantially different in sequence. In addition, unlike its eukaryotic counterparts, which have a strong preference for oxoG.C base pairs, mjOgg has little specificity for the base opposite oxoG. mjOgg has both DNA glycosylase and DNA lyase (beta-elimination) activity, and the combined glycosylase/lyase activity occurs at a rate comparable with the glycosylase activity alone. Mutation of Lys-129, analogous to Lys-241 of yOgg1, abolishes glycosylase activity.
Gogos
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Department of Biophysics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Clarke
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D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004260:DNA Repair; D043382:DNA-Formamidopyrimidine Glycosylase; D029968:Escherichia coli Proteins; D006801:Humans; D007700:Kinetics; D017017:Methanococcus / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009699:N-Glycosyl Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013816:Thermodynamics
D029968:Escherichia coli Proteins; D011994:Recombinant Proteins; D009699:N-Glycosyl Hydrolases; D043382:DNA-Formamidopyrimidine Glycosylase; C468610:DNA-formamidopyrimidine glycosylase, E coli