21. Chromosomes are packaged by wrapping 147 nucleotides around an octamer of histone proteins, forming a nucleosome . 22. There are also proteins involved in reassembling histones behind the replication fork to reestablish the nucleosome conformation. 23. NBP-45 binds specifically to nucleosome core particles, and can function as a transcriptional activator. 24. Nucleosome core particles are observed when chromatin in interphase is treated to cause the chromatin to unfold partially.25. Nucleosome remodeling has been found to cause, for instance, epigenetic silencing of DNA repair gene MLH1.26. Specific remodeling proteins are constantly altering the chromatin structure by breaking the bonds between the DNA and nucleosome . 27. Histones are basic nuclear proteins that are responsible for the nucleosome structure of the chromosomal fiber in eukaryotes. 28. Histone H1 locks the nucleosome complex together, and it is the last protein to bind in the complex. 29. Chromatin subunit models as well as the notion of the nucleosome were established in 1973 and 1974, respectively. 30. A year later, she published a paper describing the opposing effects of H1 and HMGB1 on the nucleosome .
