Centers & Labs

RIKEN Center for Life Science Technologies

Nonnatural Amino Acid Technology Team

Team Leader: Kensaku Sakamoto (Ph.D.)
Kensaku  Sakamoto(Ph.D.)

We plan to genetically encode novel and useful amino acids, in order to increase the functional and structural variety in recombinant proteins and provide unique technical supports for structural biology and epigenetics drug development, and also plan to carry forward the cell-free translation technology.

Main Research Field

Biological Sciences

Related Research Fields

Medicine, dentistry, and pharmacy

Research Subjects

  • Engineering the genetic code in living cells
  • Developing novel proteins with non-natural amino acids
  • Developing "control molecules" to regulate cellular pathways

Selected Publications

  1. Yamaguchi, A., Matsuda, T., Ohtake, K., Yanagisawa, T., Yokoyama, S., Fujiwara, Y., Watanabe, T., Hohsaka, T., and Sakamoto, K.:
    "Incorporation of a doubly functionalized synthetic amino acid into proteins for creating chemical and light-induced conjugates"
    Bioconjug Chem. 27, 198-206 (2015).
  2. Mukai, T., Yamaguchi, A., Ohtake, K., Takahashi, M., Hayashi, A., Iraha, F., Kira, S., Yanagisawa, T., Yokoyama, S., Hoshi, H., Kobayashi, T. and Sakamoto, K.:
    "Reassignment of a rare sense codon to a non-canonical amino acid in Escherichia coli"
    Nucleic. Acids Res. 43, 8111-8122 (2015).
  3. Ohtake, K., Yamaguchi, A., Mukai, T., Kashimura, H., Hirano, N., Haruki, M., Kohashi, S., Yamagishi, K., Murayama, K., Tomabechi, Y., Itagaki, T., Akasaka, R., Kawazoe, M., Takemoto, C., Shirouzu, M., Yokoyama, S., and Sakamoto, K.:
    "Protein stabilization utilizing a redefined codon"
    Sci Rep. 5: 9762 (2015).
  4. Mukai, T., Hoshi, H., Ohtake, K., Takahashi, M., Yamaguchi, A., Hayashi, A., Yokoyama, S., and Sakamoto, K.:
    "Highly reproductive Escherichia coli cells with no specific assignment to the UAG codon"
    Sci Rep. 5: 9699 (2015).
  5. Ohtake, K., Sato, A., Mukai, T., Hino, N., Yokoyama, S. and Sakamoto, K.:
    "Efficient decoding of the UAG triplet as a full-fledged sense codon enhances the growth of a prfA-deficient strain of Escherichia coli"
    J. Bacteriol. 194, 2606-2613 (2012).
  6. Hayashi, A., Hino, N., Kobayashi, T., Arai, R., Shirouzu, M., Yokoyama, S. and Sakamoto, K.:
    "Dissecting cell signaling pathways with genetically encoded 3-iodo-L-tyrosine"
    Chembiochem. 12, 387-389 (2011).
  7. Mukai, T., Hayashi, A., Iraha, F., Sato, A., Ohtake, K., Yokoyama, S. and Sakamoto, K:
    "Codon reassignment in the Escherichia coli genetic code"
    Nucleic Acids Res. 38, 8188-8195 (2010)
  8. Iraha, F., Oki, K., Kobayashi, T., Ohno. S., Yokogawa, T., Nishikawa, K., Yokoyama, S. and Sakamoto, K.:
    "Functional replacement of the endogenous tyrosyl-tRNA synthetase-tRNATyr pair by the archaeal tyrosine pair in Escherichia coli for genetic code expansion"
    Nucleic Acids Res. 38, 3682-3691 (2010).
  9. Hino, N., Hayashi, A., Sakamoto, K. and Yokoyama, S.:
    "Site-specific incorporation of non-natural amino acids into proteins in the mammalian cells with an expanded genetic code"
    Nat. protocol 1, 2957-2962 (2007).
  10. Hino, N., Okazaki, Y., Kobayashi, T., Hayashi, A., Sakamoto, K. and Yokoyama, S.:
    "Protein photo-cross-linking in mammalian cells by site-specific incorporation of a photoreactive amino acid"
    Nat. Methods 2, 201-206 (2005).

Lab Members

Principal Investigator

Kensaku Sakamoto
Team Leader

Core Members

Akira Wada
Senior Research Scientist
Akiko Matsumoto
Senior Technical Scientist
Atsushi Yamaguchi
Research Scientist
Fumie Kimura
Technical Scientist
Kazumasa Ohtake
Research Scientist
Yoshimi Amano
Technical Staff 1

Contact information

W223 2F West Research Building
1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
Tel: +81-(0)45-503-9459
Fax: +81-(0)45-503-9458

Email: sakamoto [at]

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