Mechanism for the definition of elongation and termination by the class II CCA-adding enzyme

Yukimatsu Toh, Daijiro Takeshita, Tomoyuki Numata, Shuya Fukai, Osamu Nureki, Kozo Tomita

研究成果: ジャーナルへの寄稿学術誌査読

23 被引用数 (Scopus)


The CCA-adding enzyme synthesizes the CCA sequence at the 3′ end of tRNA without a nucleic acid template. The crystal structures of class II Thermotoga maritima CCA-adding enzyme and its complexes with CTP or ATP were determined. The structure-based replacement of both the catalytic heads and nucleobase-interacting neck domains of the phylogenetically closely related Aquifex aeolicus A-adding enzyme by the corresponding domains of the T. maritima CCA-adding enzyme allowed the A-adding enzyme to add CCA in vivo and in vitro. However, the replacement of only the catalytic head domain did not allow the A-adding enzyme to add CCA, and the enzyme exhibited (A, C)-adding activity. We identified the region in the neck domain that prevents (A, C)-adding activity and defines the number of nucleotide incorporations and the specificity for correct CCA addition. We also identified the region in the head domain that defines the terminal A addition after CC addition. The results collectively suggest that, in the class II CCA-adding enzyme, the head and neck domains collaboratively and dynamically define the number of nucleotide additions and the specificity of nucleotide selection.

ジャーナルEMBO Journal
出版ステータス出版済み - 11月 2009

!!!All Science Journal Classification (ASJC) codes

  • 神経科学(全般)
  • 分子生物学
  • 生化学、遺伝学、分子生物学(全般)
  • 免疫学および微生物学(全般)


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