Fig. 3

a Parallel strand orientation of the duplex DNA freezes the mode of asymmetric cooperativity along the entire length of the strand, reducing the kinetic barrier of the hydrogen bond in the right adjacent monomer and decreasing that of the left adjacent monomer. Both the strands of the duplex DNA act in concert to incorporate asymmetric cooperativity. b Anti-parallel orientation with homo-molecular base-pairing destroys the asymmetric cooperativity because the two identical strands oppose each other’s asymmetric cooperativity mode due to their opposing orientations. c Reinstating asymmetric cooperativity requires the breaking the symmetry of homo-molecular base-pairing. Due to differences in the strengths of asymmetric cooperativity from the two strands made of different kinds of monomers, a complete cancellation of asymmetric cooperativity is avoided, leaving a resultant, comparatively weaker sequence-dependent asymmetric cooperativity. d Thus, heteromolecular base-pairing and anti-parallel strand orientation allows for sequence-dependent asymmetric cooperativity mode, leading to simultaneous replication of multiple disjoint segments independently, increasing the rate of replication. Simultaneous replication is possible because multiple segments can be unzipped independently, due to their different asymmetric cooperativity modes. e With just two monomers, information storage and unzipping kinetics are coupled, resulting in the former adversely affecting the latter. f Introduction of another pair of monomers decouples the two. Storing information does not adversely affect unzipping kinetics (g). h Low kinetic barriers in the middle of the double strand allows for rapid unzipping of the double strand during replication initiation, thus serving as origin of replication