Cairns-Smith, A. Graham (2005). Sketches for a mineral genetic material. Elements, 1: 157–161. Cairns-Smith, A. Graham (2008). Chemistry and the missing era of evolution. Chemistry: A European Journal, 14: 3830–3839. Darwin, C. (1859) The Origin of Species. John Murray, London (reprinted by Penguin Books). E-mail: grahamcs@chem.gla.ac.uk The Evolving RNA Machine for Protein Biosynthesis Ilana Agmon, Chen Davidovich, see more Anat Bashan, Ada Yonath Dept of Structural Biology, Weizmann
Institute, Rehovot 76100, Israel The ribosome’s active site, the peptidyl transferase center (PTC), resides within a highly conserved region of the large ribosomal subunit, comprised of 180 nucleotides arranged as a pseudo symmetrical two-fold region in all known structures, confining a void that provides the space required for the motions Midostaurin research buy involved in the translocation of the incoming ribosome substrates, namely the aminoacylated-tRNA molecule. Furthermore, the elaborate architecture is capable of positioning both ribosome substrates, namely the aminoacylated and the peptidyl tRNAs molecules, in stereochemistry
required for peptide bond formation and for substrate-mediated catalysis, as well as for the successive reactions, hence enabling amino acid polymerization. Consistent with comprehensive mutagenesis experiments as well as with quantum mechanical calculations, the nucleotides positioned at “walls” of this region appear to navigate this motion and their interactions with the translocating aminoacylated tRNA seem to stabilize the transition state of peptide bond formation. The overall fold of the much RNA backbone of this region
resembles motifs identified in “ancient” and “modern” RNA molecules of comparable size, regardless of their sequences. Similarly, the symmetry of this region relates the backbone fold and nucleotides orientation, but not nucleotide sequence, hence emphasizing the superiority of functional requirement over sequence conservation. The extremely high conservation of this region throughout all known kingdoms of life, the universality of its three dimensional structure, its central location within the ribosome, and the inherent tendency of RNA segment of comparable size to dimerize, support the hypothesis that the ancient ribosome evolved by gene duplication or gene fusion. Preliminary experimental results and conceptual issues will be presented and discussed. E-mail: ada.yonath@weizmann.ac.il Chemical Evolution of Peptides Bernd M. Rode, Daniel Fitz, Thomas Jakschitz Theoretical Chemistry Division, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Austria The Salt-Induced Peptide Formation (SIPF) reaction is discussed as the simplest and most plausible way for the formation of peptides under primordial earth conditions.