Abstract: 

One of the greatest mysteries in life science is how the central dogma of molecular biology, the elaborate partnership between nucleic acids and proteins, was established on the ancient earth. RNA polymerase, the pivotal protein in the central dogma, is a gigantic enzyme that catalyzes and regulates RNA synthesis in the cell. To understand how such an elaborate protein emerged, we have been trying to experimentally reconstruct the evolutional pathway from primitive peptides to RNA polymerase. Recently, we have demonstrated cationic-hydrophobic peptides can form insoluble beta-aggregates, accrete RNA on their surfaces in a size-dependent manner, and thus enhance the activities of various ribozymes. Furthermore, we have reconstructed the ancient beta-barrel conserved at the core of RNA polymerase by a homodimeric peptide only with seven amino acid types. The seven amino acids are encoded on a clearly defined area in the standard codon table (GNN and ARR). These discoveries describe the evolutional origin of the RNA-peptide partnership, RNA polymerase, and the genetic code. Implications for extraterrestrial lives will also be discussed.

Speaker: Dr. Shunsuke Tagami, RIKEN Center for Biosystems Dynamics Research.

Speaker bio: 

Shunsuke Tagami is a Team Leader in RIKEN BDR. He studied structural biology in his Ph.D. research in the University of Tokyo. Then he joined MRC Laboratory of Molecular Biology and learned RNA/protein engineering. From October 2015 he has been heading his own laboratory, which aims to understand the evolutionary pathway of natural bio-macromolecules.

Host: Tomoaki Matsuura, ELSI.

Date: Fri, 16 April, 15:30-16:30 JST (Fri, 16 April, 06:30-07:30 UTC)

Venue: Online