Diffusion‐controlled protein–DNA association: Influence of segemental diffusion of the DNA

The intrachain reaction theory of Wilemki and Fixman [(1974) J. Chem. Phys. 60 , 866–877] is used to assess the influence of internal DNA motions on various protein–DNA association schemes. It is found that, for large proteins, the diffusional association rate can be totally dominated by these motions rather than by the free‐trans‐lational diffusion rates. Also, the time required for the diffusion together of two DNA segments is estimated. This estimate can be used to provide an upper limit for the rate of intrachain cyclization, and also for the effective intrachain transfer rate of a protein bound to a DNA chain.