| | |  | | | | Record from Web of Science® | | | | | | |
| An exonuclease I-sensitive DNA repair pathway in Deinococcus radiodurans: a major determinant of radiation resistance |
|
|
| Author(s): Misra HS, Khairnar NP, Kota S, Shrivastava S, Joshi VP, Apte SK |
| Source: MOLECULAR MICROBIOLOGY Volume: 59 Issue: 4 Pages: 1308-1316 Published: FEB 2006 |
| Times Cited: 17 References: 36 |
| Abstract: Deinococcus radiodurans R1 recovering from acute dose of gamma radiation shows a biphasic mechanism of DNA double-strand break repair. The possible involvement of microsequence homology-dependent, or non-homologous end joining type mechanisms during initial period followed by RecA-dependent homologous recombination pathways has been suggested for the reconstruction of complete genomes in this microbe. We have exploited the known roles of exonuclease I in DNA recombination to elucidate the nature of recombination involved in DNA double-strand break repair during post-irradiation recovery of D. radiodurans. Transgenic Deinococcus cells expressing exonuclease I functions of Escherichia coli showed significant reduction in gamma radiation radioresistance, while the resistance to far-UV and hydrogen peroxide remained unaffected. The overexpression of E. coli exonuclease I in Deinococcus inhibited DNA double-strand break repair. Such cells exhibited normal post-irradiation expression kinetics of RecA, PprA and single-stranded DNA-binding proteins but lacked the divalent cation manganese [(Mn(II)]-dependent protection from gamma radiation. The results strongly suggest that 3' (rho) 5' single-stranded DNA ends constitute an important component in recombination pathway involved in DNA double-strand break repair and that absence of sbcB from deinococcal genome may significantly aid its extreme radioresistance phenotype. |
| Document Type: Article |
| Language: English |
| Reprint Address: Misra, HS (reprint author), Bhabha Atom Res Ctr, Div Mol Biol, Bombay 400085, Maharashtra India |
Addresses:
1. Bhabha Atom Res Ctr, Div Mol Biol, Bombay 400085, Maharashtra India |
| Publisher: BLACKWELL PUBLISHING, 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND |
| Subject Category: Biochemistry & Molecular Biology; Microbiology |
| IDS Number: 005CQ |
| ISSN: 0950-382X |
| DOI: 10.1111/j.1365-2958.2005.05005.x |
|
| | | | | | | | | Record from Web of Science® | | | | | | | | | |