Genetic analysis of DNA repair in the hyperthermophilic archaeon, Thermococcus kodakaraensis

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Abstract

Extensive biochemical and structural analyses have been performed on the putative DNA repair proteins of hyperthermophilic archaea, in contrast to the few genetic analyses of the genes encoding these proteins. Accordingly, little is known about the repair pathways used by archaeal cells at high temperature. Here, we attempted to disrupt the genes encoding the potential repair proteins in the genome of the hyperthermophilic archaeon <i>Thermococcus kodakaraensis</i>. We succeeded in isolating null mutants of the <i>hjc</i>, <i>hef</i>, <i>hjm</i>, <i>xpb</i>, and <i>xpd</i> genes, but not the <i>radA</i>,<i> rad50</i>,<i> mre11</i>,<i> herA</i>,<i> nurA</i>, and <i>xpg/fen1</i> genes. Phenotypic analyses of the gene-disrupted strains showed that the <i>xpb </i>and <i>xpd</i> null mutants are only slightly sensitive to ultraviolet (UV) irradiation, methyl methanesulfonate (MMS) and mitomycin C (MMC), as compared with the wild-type strain. The <i>hjm</i> null mutant showed sensitivity specifically to mitomycin C. On the other hand, the null mutants of the <i>hjc</i> gene lacked increasing sensitivity to any type of DNA damage. The Hef protein is particularly important for maintaining genome homeostasis, by functioning in the repair of a wide variety of DNA damage in <i>T. kodakaraensis</i> cells. Deletion of the entire <i>hef</i> gene or of the segments encoding either its nuclease or helicase domain produced similar phenotypes. The high sensitivity of the Δ<i>hef</i> mutants to MMC suggests that Hef performs a critical function in the repair process of DNA interstrand cross-links. These damage-sensitivity profiles suggest that the archaeal DNA repair system has processes depending on repair-related proteins different from those of eukaryotic and bacterial DNA repair systems using homologous repair proteins analyzed here.<br>

Journal

  • Genes & Genetic Systems

    Genes & Genetic Systems 85(4), 243-257, 2010-08-25

    The Genetics Society of Japan

References:  64

Codes

  • NII Article ID (NAID)
    10029515252
  • NII NACSIS-CAT ID (NCID)
    AA11077421
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    13417568
  • NDL Article ID
    10904800
  • NDL Source Classification
    ZR1(科学技術--生物学)
  • NDL Call No.
    Z53-W539
  • Data Source
    CJP  NDL  J-STAGE 
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