The Interaction Of Dna And Histones - The Dynamic Processes Of Nucleosome Structure

DNA is the main genetic materials in most organism. The amino acids are arranged by the genetic triplet code to synthes proteins which are very important in organism. In eukaryotic cells, DNA is located in nucleolus in the form of chromatin by combining with histone proteins.The diameter of DNA is about 2 nm, but DNA moleculer is very long in common. To human, the length of a DNA moleculer is about 100 cm. How is the long DNA moleculer located into nucleolus which is about a few microns?It is the result of interaction between DNA and histone proteins. DNA has negative charges and histone has positive ones. So the interaction between them is coulombic force. DNA wraps around histones in left-handed way and forms nucleosome structure. Many nucleosomes are linked together like "prayer beads". Then, nucleosome chain is compressed into 30 nm solenoid structure. At last, chromatin structure is formed.With the development of single moleculer manipulation.Much research work has been done on DNA by optical tweezer, magnetic tweezer, micropipe, and so on. All these work has opened a new area in molecuer biology.We numerically simulate the interaction between DNA and a histone. And we get the nucleosome structure. DNA wraps around histone about 2 loops. At the same time, we simulate the interaction between DNA and a few histones. We find DNA can wrap around histone properly in reasonable situations. At last, we propose a new model to interpret the process of DNA wrapping around histone.