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Laboratory location

Sugimoto Campus

Research Areas 【 display / non-display

Structural biochemistry

Awards & Honors 【 display / non-display

  • The 11th Symposium of Protein Society (Boston, U.S.A.) Award for Best Posters


Current Career 【 display / non-display

  • Osaka City University   Graduate School of Science   Biology and Geosciences Course   Professor  


Published Papers 【 display / non-display

  • Resistance to UV irradiation caused by inactivation of nurA and herA genes in Thermus thermophilus

    Fujii, Y., Inoue, M., Fukui, K., Kuramitsu, S., Masui, R.

    Journal of Bacteriology  200 ( 16 ) e00201-18 2018.07  [Refereed]

     View Summary

    NurA and HerA are thought to be essential proteins for DNA end resection in archaeal homologous recombination systems. Thermus thermophilus, an extremely thermophilic eubacterium, has proteins that exhibit significant sequence similarity to archaeal NurA and HerA. To unveil the cellular function of NurA and HerA in T. thermophilus, we performed phenotypic analysis of disruptant mutants of nurA and herA with or without DNA-damaging agents. The nurA and herA genes were not essential for survival, and their deletion had no effect on cell growth and genome integrity. Unexpectedly, these disruptants of T. thermophilus showed increased resistance to UV irradiation and mitomycin C treatment. Further, these disruptants and the wild type displayed no difference in sensitivity to oxidative stress and a DNA replication inhibitor. T. thermophilus NurA had nuclease activity, and HerA had ATPase. The overexpression of loss-of-function mutants of nurA and herA in the respective disruptants showed no complementation, suggesting their enzymatic activities were involved in the UV sensitivity. In addition, T. thermophilus NurA and HerA interacted with each other in vitro and in vivo, forming a complex with 2:6 stoichiometry. These results suggest that the NurA-HerA complex has an architecture similar to that of archaeal counterparts but that it impairs, rather than promotes, the repair of photoproducts and DNA cross-links in T. thermophilus cells. This cellular function is distinctly different from that of archaeal NurA and HerA.

    DOI PubMed

  • The Lon protease-like domain in the bacterial RecA paralog RadA is required for DNA binding and repair

    Inoue Masao, Fukui Kenji, Fujii Yuki, Nakagawa Noriko, Yano Takato, Kuramitsu Seiki, Masui Ryoji

    JOURNAL OF BIOLOGICAL CHEMISTRY  292 ( 23 ) 9801 - 9814 2017.06  [Refereed]

     View Summary

    Homologous recombination (HR) plays an essential role in the maintenance of genome integrity. RecA/Rad51 paralogs have been recognized as an important factor of HR. Among them, only one bacterial RecA/Rad51 paralog, RadA, is involved in HR as an accessory factor of RecA recombinase. RadA has a unique Lon protease-like domain (LonC) at its C terminus, in addition to a RecA-like ATPase domain. Unlike Lon protease, RadA's LonC domain does not show protease activity but is still essential for RadA-mediated DNA repair. Reconciling these two facts has been difficult because RadA's tertiary structure and molecular function are unknown. Here, we describe the hexameric ring structure of RadA's LonC domain, as determined by X-ray crystallography. The structure revealed the two positively charged regions unique to the LonC domain of RadA are located at the intersubunit cleft and the central hole of a hexameric ring. Surprisingly, a functional domain analysis demonstrated the LonC domain of RadA binds DNA, with site-directed mutagenesis showing that the two positively charged regions are critical for this DNA-binding activity. Interestingly, only the intersubunit cleft was required for the DNA-dependent stimulation of ATPase activity of RadA, and at least the central hole was essential for DNA repair function. Our data provide the structural and functional features of the LonC domain and their function in RadA-mediated DNA repair.

    DOI PubMed

  • Lysine propionylation is a prevalent post-translational modification in Thermus thermophilus

    Mol. Cell. Proteomics  13 ( 9 ) 2382 - 2398 2014.09  [Refereed]

  • Acetylome with structural mapping reveals the significance of lysine acetylation in Thermus thermophilus

    J. Proteome Res.  1 ( 9 ) 3952 - 3968 2013.09  [Refereed]

  • Crystal structure of the ligand-binding form of nanoRNase from Bacteroides fragilis, a member of the DHH/DHHA1 phosphoesterase family of proteins

    FEBS Lett.  587 ( 16 ) 2669 - 2674 2013.08  [Refereed]

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Books etc 【 display / non-display

  • Molecular Mechanism of the Whole DNA Repair System:A Comparison of Bacterial and Eukaryotic Systems

    増井 良治 (Part: Single Work )

    J.Nucl.Asids  2010

  • Molecular Mechanism of the Whole DNA Repair System:A Comparison of Bacterial and Eukaryotic Systems

    MASUI Ryouji (Part: Single Work )

    J.Nucl.Asids  2010

  • Enzymic reaction of proteins

    (Part: Joint Work )


  • Atomic biology in post-genome era

    (Part: Joint Work )


Review Papers (Misc) 【 display / non-display

  • Acyl-Proteome with Protein Tertiary Structure Information Reveals the Significance of Lysine Acylations

    Okanishi Hiroki, Masui Ryoji, Kim Kwang, Kuramitsu Seiki

    3 ( 1 ) 15 - 22 2018.07  [Refereed]  [Invited]

  • Structural Analysis of a Protease-like Protein with DNA-binding Activity

    The Crystallographic Society of Japan, Journal of the Crystallographic Society of Japan  60 ( 2 ) 74 - 75 2018  [Refereed]  [Invited]

  • Functional analysis of new proteases from an extremely thermophilic organism, Thermus theromphilus HB8

    Yumi Kimura, Daisuke Sasaki, Naoya Fujimura, Tadashi Ono, Chinami Sako, Suzuka Yamasaki, Ryoji Masui, Noriko Nakagawa

    PROTEIN SCIENCE  26   92 - 92 2017

  • Discovery of Lys propionylation as one of abundant post-translational modifications

    Okanishi Hiroki, Kim Kwang, Nakagawa Noriko, Kuramitsu Seiki, Masui Ryouji

    2015   183 - 183 2015

  • Molecular mechanisms of the whole DNA repair system: A comparison of bacterial and eukaryotic systems

    J. Nucleic Acids  2010   179594 2010.10

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Conference Activities & Talks 【 display / non-display

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Other educational activity and Special note 【 display / non-display

  • Contribution to FD activities


  • Class teacher


  • Contribution to FD activities


  • Class teacher