Self-sustained Replication of an RNA Enzyme
Tracey A. Lincoln and Gerald F. Joyce
Published online 2009 January 8. doi: 10.1126/science.1167856.
Le brouillon de ce post traîne dans le répertoire brouillons depuis plus d’un an. Il est temps de le poster 🙂 Je l’ai furieusement cherché sur le blog pendant plusieurs minutes 😦
Le texte est en Open Access depuis quelques mois déjà.
RNA enzymes have been made to undergo self-sustained replication in the absence of proteins, providing the basis for an artificial genetic system.
An RNA enzyme that catalyzes the RNA-templated joining of RNA was converted to a format whereby two enzymes catalyze each other’s synthesis from a total of four component substrates. These cross-replicating RNA enzymes were optimized so that they can undergo self-sustained exponential amplification at a constant temperature and in the absence of proteins or other biological materials. Amplification occurs with a doubling time of about one hour, and can be continued indefinitely. Populations of various cross-replicating enzymes were constructed and allowed to compete for a common pool of substrates. During a serial transfer experiment in which the population underwent overall amplification of >1025-fold, recombinant replicators arose and grew to dominate the population. RNA enzymes that undergo self-sustained replication can serve as an experimental model of a genetic system. Many such model systems could be constructed, allowing different selective outcomes to be related to the underlying properties of the genetic system.