A Simpler Nucleic Acid

  title={A Simpler Nucleic Acid},
  author={Leslie E. Orgel},
  pages={1306 - 1307}
  • L. Orgel
  • Published 2000
  • Chemistry, Biology
  • Science
What was the genetic material of the earliest life forms on Earth if it was not RNA? As Orgel explains in his Perspective, the answer may be simpler nucleic acid polymers perhaps like the RNA analogs called (L)-a-threofuranosyl oligonucleotides or TNAs ( SchA¶ning et al .). These molecules have threose rather than ribose in their sugar-phosphate backbones and yet retain many of the properties of RNA including the ability to pair up in double helices. 
Primitive genetic polymers.
Since the structure of DNA was elucidated more than 50 years ago, Watson-Crick base pairing has been widely speculated to be the likely mode of both information storage and transfer in the earliestExpand
RNA, Ribozymes, and Early Life Forms
It is widely accepted that present day life on Earth descended from an RNA world, although RNA-based life may not have been the very first life to exist. Expand
Darwinian evolution of an alternative genetic system provides support for TNA as an RNA progenitor.
TNA has the ability to fold into tertiary structures with sophisticated chemical functions, which provides evidence that TNA could have served as an ancestral genetic system during an early stage of life. Expand
Ribosomal proteins as documents of the transition from unstructured (poly)peptides to folded proteins.
The ribosome is the main survivor of this primordial RNA world and offers an excellent model system for retracing the steps that led to the folded proteins of today, due to its very slow rate of change. Expand
Prebiotic Chemistry and Chemical Evolution of Nucleic Acids
Nucleobases are nitrogen heterocycles that are key structural components of biological nucleic acids. Some theories for the origins of life suggest a role for environmentally supplied organicExpand
The Role of Sugar-backbone Heterogeneity and Chimeras in the Simultaneous Emergence of RNA and DNA
It has been shown that chimeric sequences—with a mixture of RNA and DNA backbones—mediate the template-directed ligation of oligomers present in mixtures of nucleic acids, enabling the simultaneous appearance ofRNA and DNA. Expand
Toward peptide nucleic acid (PNA) directed peptide translation using ester based aminoacyl transfer.
Conditions which allow template assisted intermolecular aminoacyl transfer using simple ester aminolysis chemistry primitively analogous to the ribosomal peptidyl transferase reaction in the absence of anchimeric assistance from ribose and ribosome catalysis are identified. Expand
Origin of the Genetic Code and Abiotic Synthesis of Organic Compounds
In this chapter, the main theories for the first replication systems are outlined, and possible pathways for the prebiotic synthesis of the first monomers are reviewed. Expand
Structural Insights into Conformation Differences between DNA/TNA and RNA/TNA Chimeric Duplexes
NMR measurement of kinetic and thermodynamic parameters for individual base pair opening events reveal unexpected asymmetric “breathing” fluctuations of the DNA/TNA helix and suggest that nucleic acid breathing dynamics are determined from both backbone and base contributions. Expand
RNA: Prebiotic Product, or Biotic Invention?
Recent experimental work on the assembly of potential RNA precursors is reviewed, focusing on methods for stereoselective CC bond construction by aldolisation and related processes, and the relative accessibility of RNA and alternative nucleic acids is considered. Expand


Chemical Etiology of Nucleic Acid Structure: The α-Threofuranosyl-(3'→2') Oligonucleotide System
TNAs [(L)-alpha-threofuranosyl oligonucleotides] containing vicinally connected (3'-->2') phosphodiester bridges undergo informational base pairing in antiparallel strand orientation and are capableExpand
Chemical etiology of nucleic acid structure: comparing pentopyranosyl-(2'-->4') oligonucleotides with RNA.
The alpha-arabinopyranosyl system is the strongest of all and in fact belongs to the strongest oligonucleotide base-pairing systems known. Expand
Formation of oligonucleotide-PNA-chimeras by template-directed ligation.
It is shown that ligation to form chimeras proceeds efficiently both on PNA and on DNA templates, and the relevance of these findings to discussions of possible transitions between genetic systems is discussed. Expand
L-alpha-lyxopyranosyl (4'-->3') oligonucleotides: a base-pairing system containing a shortened backbone.
[formula: see text] The L-alpha-lyxopyranosyl (4'-->3') oligonucleotide system shows cooperative base-pairing in spite of containing only five instead of the usual six covalent bonds per repetitiveExpand