Nucleosome Positioning with Set of Key Positions and Nucleosome Affinity.

The formation and precise positioning of nucleosome in chromatin occupies a very important role of study in life process. Today, many researchers discover that the positioning where the location of a DNA sequence fragment wraps around a histone in genome is not random but regular. However, the positioning is closely relevant to the concrete sequence of core DNA. So in this paper, we analyzed the relation between the affinity and sequence structure of core DNA sequence, and extracted the set of key positions. In these positions, the nucleotide sequences probably occupied mainly action in the binding. First, we simplified and formatted the experimental data by the affinity. Then, to find the key positions in the wrapping, we used neural network to analyze the positive and negative effect of nucleosome generation for every position in core DNA sequences. However, we reached a class of weights with every position to describe this effect. Finally, based on the positions with high weights, we analyzed the reason why the chosen positions are key positions, and used these positions to construct a model of nucleosome positioning predict. Experimental results show the effectiveness of our method.