PMID:17040104
| Citation |
Vidal, LS, Santos, LB, Lage, C and Leitão, AC (2006) Enhanced sensitivity of Escherichia coli uvrB mutants to mitomycin C points to a UV-C distinct repair for DNA adducts.Chem. Res. Toxicol. 19:1351-6 |
|---|---|
| Abstract |
Nucleotide excision repair (NER) in Escherichia coli repairs DNA by incising the damaged strand on the 3' and 5' sides of the lesion within pyrimidine dimers and DNA cross-linking adducts. Cross-linking adducts belong to a class of chemical damage to DNA that prevent strand separation, and thus, replication and transcription. For this reason, cross-linking agents such as mitomycin C (MC) have been used in cancer chemotherapy. The mechanisms involved in MC binding to DNA have already been defined; however, the repair of these lesions is not fully understood. Our goal was to study the repair of MC DNA lesions in E. coli cells. Several bacterial strains with specific mutations were tested for cellular inactivation and kinetics of DNA repair through analysis of DNA sedimentation profiles in alkaline sucrose gradients. The results obtained show that uvrB mutants are extremely sensitive to MC in contrast to the other isogenic uvrA and uvrC mutant strains. uvrB mutant strains are unable to repair DNA strand breaks produced by MC. Thus, UvrB might play a NER-uncoupled role in the repair of lesions induced by MC in vivo, different from its role on the repair of lesions produced by UV-C. Also it is suggested that a modified NER system is taking place in the repair of MC-adducts. |
| Links |
PubMed Online version:10.1021/tx060035y |
| Keywords |
Cell Survival; DNA Adducts; DNA Helicases; DNA Repair; Escherichia coli; Escherichia coli Proteins; Mitomycin; Mutation; Rec A Recombinases; Sensitivity and Specificity; Ultraviolet Rays |
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Main Points of the Paper
Please summarize the main points of the paper.
Materials and Methods Used
Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).
Phenotype Annotations
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| Phenotype of | Taxon Information | Genotype Information (if known) | Condition Information | OMP ID | OMP Term Name | ECO ID | ECO Term Name | Notes | Status |
|---|---|---|---|---|---|---|---|---|---|
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a mutation or genetic difference within a strain |
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OMP:0000275 |
decreased resistance to |
ECO:0000094 |
Biological Assay Data |
truncation mutation was more sensitive to lower mitomycin C concentrations than complete null mutation, uvrB301(de), due to proteins binding competition, figure 2. |
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a mutation or genetic difference within a strain |
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OMP:0000275 |
decreased resistance to |
ECO: 0000094 |
Biological assay Data |
Deletion mutants are more sensitive to DNA damaging agent Mitomycin C, figure 1 & 2. |
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a mutation or genetic difference within a strain |
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|
|
OMP:0000275 |
decreased resistance to |
ECO:0000094 |
Biological Data Assay |
Deletion mutants are more sensitive to DNA damaging agent Mitomycin C, fig 1 & 2. |
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a mutation or genetic difference within a strain |
|
|
|
OMP:0000275 |
decreased resistance to |
ECO:0000094 |
Biological Data Assay |
Deletion mutants are more sensitive to DNA damaging agent Mitomycin C, figure 1 & 2. |
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a mutation or genetic difference within a strain |
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|
OMP:0000275 |
decreased resistance to antibiotics |
ECO:0000094 |
Biological Data Assay |
Double mutation increased sensitivity to mitomycin C but at a slower rate than single deletions, figure 1. |
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a mutation or genetic difference within a strain |
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|
OMP:0000275 |
decreased resistance to |
ECO:0000094 |
Biological Data Assay |
mutants are more sensitive to DNA damaging agent Mitomycin C, fig 2. |
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a mutation or genetic difference within a strain |
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OMP:0000275 |
decreased resistance to |
ECO:0000004 |
cell fractionation data |
Double mutation was able to recover high molecular weight DNA, though at a much slower rate than wild type. See figure 4 |
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a mutation or genetic difference within a strain |
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|
OMP:0000275 |
decreased resistance to |
ECO:0000004 |
cell fractionation data |
truncation mutation was more sensitive to mitomycin C treatments resulting in increasing amounts of DNA strand breaks. See figure 4 |
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| edit table |
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Notes
- This is the paper used in the OMP tutorial. As such it is generally reviewed and changed often.
References
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