Taiwan Protein Project (TPP), directed by Academician Ming-Daw Tsai[1], is a program supported by the Executive Yuan’s policy quota. In addition to performing frontier research, an important mission of TPP is to assist domestic industry to solve protein-related problems.

TPP recently worked with Personal Genomics, Inc. (PGI), to help demonstrate the feasibility of a new method for next generation DNA sequencing proposed by PGI. The work has been published recently in Nature Research-Communications Biology on June 20, 2019.

At present, the most commonly used DNA sequencing approach is the “cyclic reversible terminator” (CRT) approach of Illumina[2]. However, this method has its limitations in the need to pause for cleavage at each cycle, the residual fluorescent label at the nucleobase not cleaved completely in each cycle, and the relatively short read length. Despite the development of many highly efficient DNA sequencing methods over the past four decades, there is room and need for further development and improvement, the research team said.

The research team first showed that 3’-esterified dNTP can be incorporated into a template-primer DNA by Thermococcus sp. 9°N DNA polymerase, and solved the crystal structures of the reaction intermediates and products. Then they showed that the reaction can occur continuously. Finally, they used 5’-FAM-labeled primer and esterified dNTP with a dye to show that the reaction can proceed to ca. 450 base pairs, and that the intermediates of many individual steps can be identified. Academician Tsai said, “The results demonstrate the feasibility of a 3’-editing based DNA sequencing method that could find practical applications after further optimization.”

This cooperative research involved Academician Ming-Daw Tsai and other TPP members including Dr. Wen-Jin Winston Wu and Dr. Manuel Maestre-Reyna, along with the PGI team including Dr. Shiuan-Woei LinWu (the first author), Dr. Chung-Fan Chiou, and its board director and CEO Dr. Johnsee Lee.

The team has worked closely for nearly three years to lead to the present publication. A new method for DNA sequencing is also likely to benefit the development of disease diagnosis, and drug development.

Figure：The results demonstrate the feasibility of a 3’-editing based DNA sequencing method that could find practical applications after further optimization.

The publication can be found at：https://www.nature.com/articles/s42003-019-0458-7

Taiwan Protein Project (TPP)：http://tpp.sinica.edu.tw

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[1] Academician Ming-Daw Tsai is a Distinguished Research Fellow in the Institute of Biological Chemistry, Academia Sinica

[2] cyclic reversible terminator is based on the incorporation of 3’-blocked terminators, followed by chemical reactions to remove the fluorophore from the nucleobase and restore the 3’-OH group.