1 / 17

Origin of Life: Molecular Deal between Peptides and Nucleic Acids

This article explores the origin of life and the role of a "molecular deal" between lipophilic peptides and hydrophilic nucleic acids. It proposes that this deal helped overcome the selection obstacles faced by both compounds, allowing for the development of the genetic code and translation. The article cites relevant studies and models that support this proposition.

tseim
Download Presentation

Origin of Life: Molecular Deal between Peptides and Nucleic Acids

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Basic Questions about the Origin of LifeONTHE GENETIC CODE HOW DID TRANSLATION OCCUR ? A ‘MOLECULAR DEAL’ between lipophilic peptides and hydrophilic nucleic acids helped to overcome the major selection obstacle of each class of compounds : Too low mobility and irreversible precipitation of peptides. Too high mobility and infinite dilution of nucleic acids. A proposition by Peter Strazewski, Lyon

  2. Angewandte Chemie International Edition in English, 1972, 11, 798-830 1972

  3. Angewandte Chemie International Edition in English, 1981, 20, 500-520

  4. Angewandte Chemie International Edition in English, 1981, 20, 500-520

  5. Journal of Molecular Evolution, 1989, 29, 465-474 A) 3'-aminoacyl-RNA B) Uncoded peptidyl transfer C) mRNA-encoded peptidyl transfer (PT) D) ribosome-catalysed and mRNA-encoded PT

  6. Eörs Szathmáry in: «Evolution: from Cosmogenesis to Biogenesis» (B. Lukacs et al. eds.) KFKI1990, 50/C, 77-83

  7. Early Middle Late A1-AMP A3-tRNA3 A3-tRNA3 + A2-A3-tRNA3 + A1-A2-tRNA2 + A1-A2-tRNA2 A1-A2-A3-tRNA3 === === III Template RNA Origin of genetically encoded protein synthesis : A model based on selection for RNA peptidation Origin of Life and Evolution of the Biosphere, 1991, 21, 165-176 Jeffrey Tze-Fei Wong A) 3'-aminoacyl-AMP + 3'-peptidyl-RNA B) Uncoded peptidyl transfer C) mRNA-encoded peptidyl transfer

  8. On the origin of protein synthesis : A speculative model based on hairpin RNA structures Journal of Theoretical Biology, 1994, 171, 303-8 Massimo Di Giulio A) Uncoded peptidyl transfer through (bulged) double-strand formation between 3'-aminoacyl-RNA hairpin (+) RNA hairpin (+) 5'-aminoacyl-RNA hairpin => 5'-dipeptidyl-RNA hairpin (-) 5'-aminoacyl-RNA hairpin (-) 5'-dipeptidyl-RNA hairpin (-) B) Stabilisation of cruciforms between the above hairpins through mRNA C) mRNA-encoded peptidyl transfer between 3'-aminoacyl and 3'-peptidyl-tRNAs D) rRNA-catalysed peptidyl transfer

  9. 1994

  10. 1994 (reproduced from 1987)

  11. Experimentally taken care of by: John D. Sutherland, Manchester, UK Prebiotic Aminoacylation of Nucleotides Chemistry & Biodiversity2004, 1, 203-246

  12. More contributions to the origin of tRNA as a basis for the appearance of the genetic code and translation(and replication) : Manfred Eigen, Peter Schuster, Ruthild Winkler 1972, 1981, 1989 Jeffrey Tze-Fei Wong 1975-2006, ... Massimio Di Giulio 1989-2006, ... Toby Gibson & Angus Lamond 1990 Tobias Dick & Wolfgang Schamel 1995 Nancy Maizels & Alun Weiner 1987-1999 ... Importance of compartmentalisation and the matrix effect : William Hargreaves, Sean Mulvihill, David Deamer et al. 1977- ... Pier Luigi Luisi, Peter Walde, Evelyne Blöchliger, Markus Blocher et al. 1998-2004 Jack Szostak, Martin Hanczyc 2001- ...

  13. MAJOR PLAYERS NUCLEIC ACIDS replicate primary sequence PROTEINS recognise SUGARS recognise LIPIDS replicate shape HYDROPHILES AMPHIPHILES

  14. hydrophilic A-RNA hairpin-3'-oligopeptide lipophilic A-RNA a-helix ACCA stack helix dipole shallow groove 5’-RNA-3’-(Ala)21 deep groove UUCG loop deep groove UUCG loop ACCA stack a-helix shallow groove shallow groove

  15. hydrophilic A-RNA hairpin-3'-oligopeptide lipophilic A-RNA b-strand ACCA stack 5’-RNA-3’-(Ala)21 UUCG loop shallow groove deep groove

  16. love you both MOLECULAR DEAL N.A. to P.P.: « I'll help you to stay in solution, if you help me not to get washed away » P.P. to N.A.: « I'll help you to stick around, if you help me to hold sufficient distance to my buddies »

More Related