The evolution of the protein synthesis system

An evolutionary picture of the early protein synthesis was presented in relation to the problem of the origin and the evolution of life. A model of an autocatalytic system was studied in this connection. The system in this model included a template nucleotide and two activated amino acid polymerases with or without a nucleotide polymerase. Variables defining the system were: (1) Catalytic activity of the polymerases, (2) Number of amino acid residues at the activity site of the polymerases, (3) Number of amino acid residues at the selectivity site of the polymerases, (4) Number of the polymerases, (5) Accuracy of polymerization and activity of the polymerases, (6) Number of evolutionary improvements, and (7) The probability of an occurrence of beneficial mutations. The population changes of the systems were obtained by computer calculations. The simulation results indicated that even a very small enzymic activity and specificity of the polymerases could eventually lead the system to the most accurate protein synthesis, as far as transitions to systems with higher accuracy were allowed. The model study would encourage further quantiative investigations on catalytic activities of synthetic peptides, and on interactions between nucleotides and amino acids, and constructions of autocatalytic systems from a chemical evolutionary point of view.This is a part of a dissertation of HM to be presented to the Graduate School of the University of Maryland in partial fulfilment of the requirements for the Ph.D.