The minireview presents recent results obtained in the experiments with DNA minicircles containing reconstituted nucleosomes. This system allows one to register and to characterize conformational dynamics of nucleosomes and of subnucleosomal particles containing histone tetramer (H3-H4)2. In particular, it has revealed an important role of the histone N-terminal tails in this dynamics. Solution of the linking number paradox and relevance of the results obtained to chromatin structural dynamics are discussed.