A Model for the Evolution of Nucleotide Polymerase Directionality

摘要

BackgroundIn all known living organisms, every enzyme that synthesizes nucleic acid polymers does so by adding nucleotide 5′-triphosphates to the 3′-hydroxyl group of the growing chain. This results in the well known directionality of all DNA and RNA Polymerases. The lack of any alternative mechanism, e.g. addition in a direction, may indicate a very early founder effect in the evolution of life, or it may be the result of a selective pressure against such an alternative.