YAC libraries can be generated in which the regions cloned span the whole genome of the organism of interest. C. DNA sequence comparisons can be used to identify important regions of genomes. B. Histones are present in large quantities and associate with DNA to form nucleosomes 1. Histones contain a large number of positively charged amino acids that aid in binding negatively charged DNA 2. The five types of histones can be broken into H1 and nucleosomal histones.
Nucleosomal histones show a very high level of conservation.
C. Nucleosomes are formed by the winding of DNA around nucleosomal histones. D. Linker regions of DNA are exposed between nucleosomes. This is where micrococcal nuclease cuts. E. Nucleosomes are then packed into higher order structures. F. Transcriptionally active regions of DNA appear to be less highly packed than transcriptionally inactive areas.