Open AccessPurification and characterization of a mammalian homolog of Escherichia coli MutY mismatch repair protein from calf liver mitochondria
Author(s) -
Antony R. Parker,
Yesong Gu,
A-Lien Lu
Publication year - 2000
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/28.17.3206
Subject(s) - dna glycosylase , biology , escherichia coli , microbiology and biotechnology , biochemistry , guanine , dna , gel electrophoresis , molecular mass , western blot , mitochondrion , polyacrylamide gel electrophoresis , dna repair , gene , enzyme , nucleotide
A protein homologous to the Escherichia coli MutY glycosylase, referred to as mtMYH, has been purified from calf liver mitochondria. SDS-polyacrylamide gel electrophoresis, western blot analysis as well as gel filtration chromatography predicted the molecular mass of the purified calf mtMYH to be 35-40 kDa. Gel mobility shift analysis showed that the purified mtMYH formed specific binding complexes with A/8-oxoG, G/8-oxoG and T/8-oxoG, weakly with C/8-oxoG, but not with A/G and A/C mismatches. The purified mtMYH exhibited DNA glycosylase activity removing adenine mispaired with G, C or 8-oxoG and weakly removing guanine mispaired with 8-oxoG. The mtMYH glycosylase activity was insensitive to high concentrations of NaCl and EDTA. The purified mtMYH cross-reacted with antibodies against both intact MutY and a peptide of human MutY homolog (hMYH). DNA glycosylase activity of mtMYH was inhibited by anti-MutY antibodies but not by anti-hMYH peptide antibodies. Together with the previously described mitochondrial MutT homolog (MTH1) and 8-oxoG glycosylase (OGG1, a functional MutM homolog), mtMYH can protect mitochondrial DNA from the mutagenic effects of 8-oxoG.