Seminar: HOWARD LECTURE -- The Peptido RNA World (HOWARD LECTURE -- Prof. Clemens Richert)

Tuesday, 1 October 2019 - 3:30pm – Tuesday, 1 October 2019 - 4:30pm  |  Rupert Myers Theatre

Abstract

All known organisms use translation for protein synthesis. Translation is an RNA-mediated process. The template that provides the sequence information is a messenger RNA, the adaptor molecule that brings the amino acid to the growing polypeptide chain is a transfer RNA, and the core parts of the ribosome that act as catalyst are made up of RNA. 

It is rather unlikely that the ribosomal machinery evolved in one step. There must have been a simpler form of RNA-induced peptide synthesis that started a molecular evolution leading to present-day translation. This simpler system must have been based on RNA molecules. There have been several proposals for how translation may have started in a prebiotic scenario,1,2,3,4 but a robust experimental system that shows RNA-induced peptide growth from amino acids in the absence of an enzyme or ribozyme has been lacking. We have recently discovered the first experimental system in which peptide growth occurs simultaneously with the formation of RNA chains and genetic copying.5,6 In this system, amino acids, ribonucleotides and precursors of cofactors react in a cold aqueous solution containing a strong organic condensing agent to give small biomacromolecules. In assays that occur without intervention of an experimentalist, amino acids are bound by ribonucleotides or short RNA strands in covalent form.  The covalent capture changes the reactivity such that accelerated peptide chain growth results, based on the intrinsic reactivity of the molecules involved.7 We have now found out why the life-like reaction system is so efficient, and we propose the term "organocapture" for the phenomenon.9

 

References

  1. Paecht-Horowitz, M.; Berger, J.; Katchalsky, A. Nature 1970, 228, 636.
  2. Orgel, L.E. J. Mol. Evol. 1989, 29, 465.
  3. Sutherland, J.D.; Blackburn, J.M. Chem. Biol. 1997, 4, 481.
  4. Turk, R.M.; Illangasekare, M.; Yarus, M. J. Am. Chem. Soc. 2011, 133, 6044.
  5. Jauker, M.; Griesser, H.; Richert, C. Angew. Chem. Int. Ed. 2015, 54, 14559.
  6. Jauker, M.; Griesser, H.; Richert, C. Angew. Chem. Int. Ed. 2015, 54, 14564.
  7. Griesser, H.; Tremmel, P.; Kervio, E.; Pfeffer, C.; Steiner, U.E.; Richert, C. Angew. Chem. Int. Ed. 2017, 56, 1219.
  8. Griesser, H.; Bechthold, M.; Tremmel, P.; Kervio, E.; Richert, C. Angew. Chem. Int. Ed. 2017, 56, 1224.
  9. P. Tremmel, H. Griesser, U. E. Steiner, C. Richert, Angew. Chem. Int. Ed. 2019, 58, 13087-13092

Clemens Richert graduated from the University of Muenster (B.S) and Cologne (M.S) to go onto complete a PhD in human biology (Munich university, 1993) and Chemistry (Supervisor Steve Benner, ETH Zurich, 1994). He is now the head of the Institute for Organic Chemistry at the University of Stuttgart, where he focuses non-enzymatic formation of important molecules involved in the origin of life.