Question 1: Peptide nucleic acids and the origin and homochirality of life.
The possibilities of pseudo peptide DNA mimics like PNA (peptide nucleic acid) having a role for the prebiotic origin of life prior to an RNA world is discussed. In particular a scenario is proposed in which protocells with an achiral genetic material through several generations stepwise is converted into a chiral genetic material, e.g., by incorporation of RNA units. Provided that a sufficiently large sequence space is occupied, a selection process based on catalytic function in which a single cell (first common ancestor) has a definite evolutionary advantage, selection of this cell would by contingency also lock it into homochirality.
Nielsen
Peter E
PE
Department of Cellular and Molecular Medicine, University of Copenhagen, The Panum Institute, Blegdamsvej 3c, DK-2200, Copenhagen N, Denmark. pen@imbg.ku.dk
D005075:Biological Evolution; D019369:Life; D008968:Molecular Conformation; D015394:Molecular Structure; D000069497:Origin of Life; D020135:Peptide Nucleic Acids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D020135:Peptide Nucleic Acids; D012313:RNA