(private-note)Paranemic cohesion is a solution to the problem of how to assemble topologically closed DNA (and RNA?) structures. No "sticky ends" or other base-pairings are needed. The mechanism is best explained looking at the figures of this short but nice paper.

(private-note)A great overview / viewpoint article stating 6 reasons for the importance of self assembly and defining important terms like "static self-assembly" vs "dynamic self-assembly" (those continuously dissipating energy). Favorite citation: "A difficulty in studying self-assembly in living cells (and in many nonliving systems) is that it is impractical to change many of the parameters that determine the behavior of the system the components and the interactions among them--and thus difficult to test hypotheses relating structures and properties of these components and the aggregates that they form. We wished to have available a set of self-assembling components in which these parameters could be changed easily, in order to understand (and to be able to manipulate) the processes by which components self-assembled into aggregates. "