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Characterization of 2-hydroxyadenine DNA glycosylase activity of Escherichia coli MutY protein.
- Source :
-
International Journal of Radiation Biology . Jul2002, Vol. 78 Issue 7, p585-592. 8p. - Publication Year :
- 2002
-
Abstract
- Purpose: 2-Hydroxyadenine (2-ohA) is an oxidation product of adenine generated in DNA by ionizing radiation and various chemical oxidants. 2-ohA has mutational potential comparable to that of 8-oxoguanine in bacteria and mammalian cells. Recent studies have shown that 2-ohA is removed from DNA by a human MutY homolog, MYH protein, in vitro. On the other hand, the repair mechanisms for 2-ohA in Escherichia coli are not yet understood. Materials and methods: Gel shift assays were used to assess the binding activity of E. coli full-length MutY protein and its N-terminal (residues 1-226) domain (M25) to 2-ohA/G-, 2-ohA/A-, 2-ohA/C- and 2-ohA/T-containing 24-mer oligonucleotides. Furthermore, whether these proteins specifically cleave 2-ohA-containing duplex oligonucleotides was examined. Results: The purified MutY and M25 proteins had similar binding affinities to 2-ohA/G-, 2-ohA/A- and 2-ohA/C-containing oligonucleotides. MutY protein removed 2-ohA preferentially from 2-ohA/G mispairs. M25 protein showed the reduced catalytic activity for 2-ohA/G-containing oligonucleotides. Conclusions: E. coli MutY protein has a DNA glycosylase activity that removes 2-ohA from 2-ohA/G mispairs in DNA. The C-terminal domain is required for the removal of 2-ohA from DNA, but is not crucial for binding to 2-ohA-containing oligonucleotides. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ADENINE
*DNA
*ESCHERICHIA coli
*GENETIC mutation
Subjects
Details
- Language :
- English
- ISSN :
- 09553002
- Volume :
- 78
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- International Journal of Radiation Biology
- Publication Type :
- Academic Journal
- Accession number :
- 6886049
- Full Text :
- https://doi.org/10.1080/09553000210130560