English: Langevin Dynamics of a 30 kb permanent loop formed in a 1 Mb region of chromatin fiber, as in Figure 2. The polymer is colored according to the facilitation arrangement, where the loop (black) occurs in the region between the enhancer (yellow) and the promoter (blue). The movie is presented at a rate of 1000 simulated time-steps per one second of real time; every seventh frame of the movie corresponds to a computationally obtained conformation, with quadratic interpolation performed between subsequent conformations (done to avoid high-frequency fluctuations between neighboring frames). The total simulation time for each run of each parameter set was approximately 5,000 times longer than the part of simulation displayed in this movie.