Deinococcus radiodurans RecA nucleoprotein filaments characterized at the single-molecule level with optical tweezers
| Autor: | Dmitrii Baitin, Mikhail Khodorkovskii, Aleksandr Alekseev, Natalia Morozova, Galina Cherevatenko, Anton Sabantsev, A D Vedyaykin, Oksana Kovaleva, Georgii Pobegalov |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
DNA Repair
Optical Tweezers DNA repair Biophysics medicine.disease_cause Biochemistry chemistry.chemical_compound Bacterial Proteins medicine Deinococcus Molecular Biology Escherichia coli Persistence length biology Escherichia coli Proteins Deinococcus radiodurans Cell Biology Microfluidic Analytical Techniques biology.organism_classification Molecular biology Biomechanical Phenomena Nucleoprotein DNA-Binding Proteins Rec A Recombinases Nucleoproteins chemistry Protein Multimerization Homologous recombination DNA |
| Zdroj: | Biochemical and Biophysical Research Communications. 466:426-430 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/j.bbrc.2015.09.042 |
| Popis: | Deinococcus radiodurans can survive extreme doses of ionizing radiation due to the very efficient DNA repair mechanisms that are able to cope even with hundreds of double-strand breaks. RecA, the critical protein of homologous recombination in bacteria, is one of the key components of the DNA-repair system. Repair of double-strand breaks requires RecA binding to DNA and assembly of the RecA nucleoprotein helical filaments. The Escherichia coli RecA protein (EcRecA) and its interactions with DNA have been extensively studied using various approaches including single-molecule techniques, while the D. radiodurans RecA (DrRecA) remains much less characterized. However, DrRecA shows some remarkable differences from E. coli homolog. Here we combine microfluidics and single-molecule DNA manipulation with optical tweezers to follow the binding of DrRecA to long double-stranded DNA molecules and probe the mechanical properties of DrRecA nucleoprotein filaments at physiological pH. Our data provide a direct comparison of DrRecA and EcRecA binding to double-stranded DNA under identical conditions. We report a significantly faster filaments assembly as well as lower values of persistence length and contour length for DrRecA nucleoprotein filaments compared to EcRecA. Our results support the existing model of DrRecA forming more frequent and less continuous filaments relative to those of EcRecA. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect