Abstract
The purification and characterization of a pyrimidine dimer-specific glycosylase/AP lyase from Bacillus sphaericus (Bsp-pdg) are reported. Bsp-pdg is highly specific for DNA containing the cis-syn cyclobutane pyrimidine dimer, displaying no detectable activity on oligonucleotides with trans-syn I, trans-syn II, (6-4), or Dewar photoproducts. Like other glycosylase/AP lyases that sequentially cleave the N-glycosyl bond of the 5' pyrimidine of a cyclobutane pyrimidine dimer, and the phosphodiester backbone, this enzyme appears to utilize a primary amine as the attacking nucleophile. The formation of a covalent enzyme-DNA imino intermediate is evidenced by the ability to trap this protein-DNA complex by reduction with sodium borohydride. Also consistent with its AP lyase activity, Bsp-pdg was shown to incise an AP site-containing oligonucleotide, yielding β- and δ-elimination products. N-terminal amino acid sequence analysis of this 26 kDa protein revealed little amino acid homology to any previously reported protein. This is the first report of a glycosylase/AP lyase enzyme from Bacillus sphaericus that is specific for cis-syn pyrimidine dimers. Copyright (C) 2000 Elsevier Science B.V.
Original language | English (US) |
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Pages (from-to) | 307-316 |
Number of pages | 10 |
Journal | Mutation Research - DNA Repair |
Volume | 459 |
Issue number | 4 |
DOIs | |
State | Published - May 31 2000 |
Externally published | Yes |
Keywords
- Bacillus sphaericus
- Glycosylase/AP lyase
- Pyrimidine dimer
ASJC Scopus subject areas
- Molecular Biology
- Toxicology
- Genetics