Peptide nucleic acids , information transfer

Schmidt J.G., Nielsen P.E., Orgel L. E. Information transfer from peptide nucleic acids to RNA by template-directed syntheses. Nucleic Acids Res. 1997 25 4797- 802. 

Although many questions are still open, peptide nucleic acids are easier to synthesize via simple reaction routes than is natural RNA. The PNAs have another important advantage they are achiral and uncharged, i.e., they contain no chiral centres in the polymeric backbone (see Sect. 9.4). Unfortunately, however, they do not fulfil all the necessary conditions for molecular information storage and transfer. Thus, the search for other possible candidates for a pre-RNA world continues. 

The scientific world was amazed to hear that David Lee, from the laboratory of Reza Ghadiri (Scripps Research Institute, La Jolla, California), had found a self-replicating peptide (Lee et al., 1996) there are analogies to the experiments with oligonucleotides (see Sect. 6.4). Lee was able to show that a certain peptide, containing 32 amino acids, can both function as a matrix and also support its own synthesis autocatalytically. The information transfer is clearly more complex than that involved in nucleic acid replication. In the case of this particular peptide, both the... 

While peptide antibiotics are synthesized according to enzyme-controlled polymerization patterns, both proteins and nucleic acids are made by template mechanisms. Tire sequence of their monomer emits is determined by genetically encoded information. A key reaction in the formation of proteins is the transfer of activated aminoacyl groups to molecules of tRNA (Eq. 17-36). Tire tRNAs act as carriers or adapters as explained in detail in Chapter 29. Each aminoacyl-tRNA synthetase must recognize the correct tRNA and attach the correct amino acid to it. The tRNA then carries the activated amino acid to a ribosome, where it is placed, at the correct moment, in the active site. Peptidyltransferase, using a transacylation reaction, in an insertion mechanism transfers the C terminus of the growing peptide chain onto the amino group of... 

---