The interface at (A*) contains a free 3' OH that is chemically suitable for the reaction catalysed by replicative polymerases, and the "overhang" configuration is structurally suitable for chain elongation by a replicative polymerase.
A interface en (A*) contén un 3' OH libre que é quimicamente axeitado para a reacción catalizada polas polimerases replicativas, e a configuración cunha parte que sobresae é estruturalmente axeitada para a elongación da cadea polas polimerases replicativas.