- Koji Tamura: Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
Recent analysis of samples from asteroids Ryugu and Bennu did not reveal any significant amino acid enantiomeric excesses, and these facts appear to contradict the most prevailing view that a slight enantiomeric excess of L-amino acids present on the primitive Earth is the origin of homochirality. From the perspective of continuity in biological evolution, it would again be considered a strong possibility that primordial tRNA aminoacylation could have led to preferential homochiral (L-) protein biosynthesis on the early Earth (Tamura- Schimmel model), and that RNA played a major role in the generation of amino acid homochirality. The results of recent molecular dynamics simulations have also clarified the mechanism of its chiral selectivity.