Fig. 1. ATP-fueled dynamization of phosphodiester bonds by simultaneous action of two antagonistic DNA enzymes for transient dynamic covalent polymerization of DNA strands with tunable lifetimes and adjustable steady-state dynamics.

(A) Short telechelic DNA monomers, M₁, with 4-nt self-complementary ssDNA ends are covalently joined via T4 DNA ligase–catalyzed phosphodiester bond formation under consumption of two ATP fuel molecules. This ligation forms the recognition site (highlighted by the orange box) of the endonuclease BamHI, which counteracts ligation by catalyzing the cleavage (restriction path as red line) of the just formed phosphodiester bonds. Simultaneous ligation and cutting at this site creates a dynamic covalent bond until the ATP runs out. (B) Transient growth of dynamically polymerizing DNA chains in a closed system is achieved by a faster ligation than restriction reaction (v_act ≫ v_deact). The lifetime is coupled to the ATP fuel and can be tuned together with the DySS properties of the dynamic covalent DNA chains under biocatalytic control.