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Bleomycin resistance conferred by a drug-binding protein
A Gatignol1, H Durand, G Tiraby
1Laboratoire de Microbiologie et Génétique Appliquées du CNRS, CRBGC, Université Paul Sabatier, Toulouse, France.
FEBS Letters
|March 28, 1988
Summary
A novel bleomycin-binding protein was purified and shown to inhibit DNA cleavage by bleomycin. This protein sequesters bleomycin, explaining cellular resistance conferred by the ble gene.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Bleomycin is an anticancer drug that functions by cleaving DNA.
- Cellular resistance to bleomycin can be mediated by specific genes, such as the ble gene found in actinomycetes.
Purpose of the Study:
- To purify and characterize the protein encoded by the bleomycin-resistance gene (ble).
- To investigate the mechanism by which this protein confers bleomycin resistance.
Main Methods:
- Cloning the ble gene into a recombinant Escherichia coli (E. coli) strain.
- Purification of the bleomycin-binding protein from E. coli culture.
- In vitro assays to determine the interaction between the purified protein and bleomycin.
Main Results:
- The purified protein binds bleomycin in a reversible, one-to-one ratio.
- Bleomycin bound by the protein loses its DNA-cleaving activity.
- The protein effectively sequesters bleomycin, preventing DNA damage.
Conclusions:
- The bleomycin-binding protein acts as a molecular shield, protecting DNA from bleomycin-induced cleavage.
- The sequestering activity of this protein is the primary mechanism underlying bleomycin resistance conferred by the ble gene.