Alternative forms of formamidopyrimidine-DNA glycosylase from Arabidopsis thaliana.
Formamidopyrimidine-DNA glycosylase (FPG) catalyzes the initial steps in the repair of DNA containing oxidized purines. Two complementary DNA clones encoding homologs of bacterial FPG, designated Atfpg-1 and Atfpg-2, have been isolated from Arabidopsis thaliana. They are products of alternative splicing of the transcript of a single gene. Proteins encoded by both clones, AtFPG-1 and AtFPG-2, engineered to contain oligohistidine sequences on their C-terminal ends, were expressed in Escherichia coli and purified, and their activities were assayed. Both proteins cleaved DNA that contained apurinic sites, indicating that they have abasic lyase activity. AtFPG-1, but not AtFPG-2, showed significant cleavage of a double-stranded oligonucleotide that contained 8-oxo-guanine, indicating that the structural differences between the two proteins influence their enzymatic activities. However, both proteins were able to cleave the same sites in DNA that was treated with visible light in the presence of methylene blue.
Section of Plant Biology, University of California, One Shields Avenue, Davis, CA 95616, USA.
M J
MJ
Gao
T M
TM
Murphy
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004260:DNA Repair; D043382:DNA-Formamidopyrimidine Glycosylase; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D017931:DNA Primers; D043382:DNA-Formamidopyrimidine Glycosylase; D029968:Escherichia coli Proteins; D009699:N-Glycosyl Hydrolases; D011994:Recombinant Proteins; C468610:DNA-formamidopyrimidine glycosylase, E coli; C468606:MMH-1 protein, Arabidopsis; C468608:FPG3 protein, Arabidopsis