title: The fidelity of template-directed oligonucleotide ligation and the inevitability of polymerase function.
abstract: The first living systems may have employed template-directed oligonucleotide ligation for replication. The utility of oligonucleotide ligation as a mechanism for the origin and evolution of life is in part dependent on its fidelity. We have devised a method for evaluating ligation fidelity in which ligation substrates are selected from random sequence libraries. The fidelities of chemical and enzymatic ligation are compared under a variety of conditions. While reaction conditions can be found that promote high fidelity copying, departure from these conditions leads to error-prone copying. In particular, ligation reactions with shorter oligonucleotide substrates are less efficient but more faithful. These results support a model for origins in which there was selective pressure for template-directed oligonucleotide ligation to be gradually supplanted by mononucleotide polymerization.
authors.affiliation: Department of Chemistry, Indiana University, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: James
authors.forename: A D
authors.initials: AD
authors.lastname: Ellington
mesh_terms: D001483:Base Sequence; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000378:metabolism*; D013698:Templates, Genetic
chemical_list: D009841:Oligonucleotides; D004259:DNA-Directed DNA Polymerase