The Earth was born about 4.6 billion years ago, and life is thought to have originated in the primordial oceans about 3.8 billion years ago. What characteristics did life on Earth have?
The genetic code is the algorithm that connects RNA triplet and an amino acid through all of the biological systems, that is, archaeal, bacterial and eukaryotic systems. We are focusing on the analysis of aminoacylation of tRNA by aminoacyl-tRNA synthetases and its relationship to the origin of the genetic code. tRNA is the molecule that Francis Crick predicted as an adaptor between DNA sequences and amino acids sequences. And the peptide bond formation by aminoacyl-tRNAs on the ribosome is another important step in biological system.
Aminoacylation of RNA minihelices (primitive forms of modern tRNAs) is speculated to be a key step in the transition from the putative RNA world to the theater of proteins. Here chiral preference of aminoacylation was shown with an RNA-directed aminoacylation system, suggesting the possibility that the selection of L-amino acids for proteins was determined by the stereochemistry of RNA. In addition, peptide bond formation could be achieved without the ribosome, but with a simple, minimized system that captures the essence of an interaction seen in the ribosome.
Aminoacylation of tRNA by aminoacyl-tRNA synthetase and peptide bond formation on the ribosome are fundamental reactions in all living organisms. We believe that the origins of these reactions are related to the essential meaning of living systems.
Episode Links:
Koji Tamura's Website:
kojitamura.web.fc2.com
Origin of Amino Acid Homochirality:
www.scripps.edu/newsandviews/...
www.tus.ac.jp/en/mediarelatio...
Evolution of tRNA and the Genetic Code:
www.tus.ac.jp/en/mediarelatio...
Origin of the Ribosome (Peptidyl Transferase Center):
www.tus.ac.jp/en/mediarelatio...
Nature "NEWS FEATURE":
www.tus.ac.jp/en/news/archive...
Correction:
10:56 "5 μM α + β" should be corrected to "0.5 μM α + β".
#東京理科大学 #TUS #Tokyo University of Science #Koji Tamura #Origin of Life
#tRNA #Homochirality #Ribosome #Amino Acid
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