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Author Pobegalov, Georgii ♦ Cherevatenko, Galina ♦ Alekseev, Aleksandr ♦ Sabantsev, Anton ♦ Kovaleva, Oksana ♦ Vedyaykin, Alexey ♦ Morozova, Natalia ♦ Baitin, Dmitrii ♦ Khodorkovskii, Mikhail
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ DNA REPAIR ♦ ESCHERICHIA COLI ♦ FILAMENTS ♦ GENE RECOMBINATION ♦ IONIZING RADIATIONS ♦ MOLECULES ♦ NUCLEOPROTEINS ♦ PH VALUE ♦ STRAND BREAKS
Abstract 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. - Highlights: • We investigate Deinococcus radiodurans RecA interactions with long double-stranded DNA at the single-molecule level. • At physiological pH D. radiodurans RecA forms nucleoprotein filaments significantly faster relative to Escherichia coli RecA. • D. radiodurans RecA-dsDNA nucleoprotein filaments are more flexible and slightly shorter compared to those of E. coli RecA.
ISSN 0006291X
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-10-23
Publisher Place United States
Journal Biochemical and Biophysical Research Communications
Volume Number 466
Issue Number 3


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