The goals of this study are (1) expression of individual histone H1 variants, (2) quantitation of their interactions with DNA of defined sequence, (3) determination of the effects of histone binding on the conformation of DNA utilizing CD spectroscopy, and (4) determination of the roles of various H1 domain structures in the interaction with DNA. The results of this work will help clarify the nature of the interactions of relatively non-specific DNA-binding proteins with DNA. These studies will provide a preliminary indication of the nature of structure-function correlations in histone:DNA interactions. %%% The complexity of eucariotic organisms dictates a requirement for large DNA structures which can only be accomodated in the limited volume of the living cell by means of interactions with proteins such as the histones which wrap the DNA into tightly packed structures which nonetheless permit access of the cell's biosynthetic machinery to the DNA. The studies proposed investigate the interaction of naturally occurring variants of histone H1. The histones are extremely difficult to purify. This study involves the novel use of pure histones produced by molecular biological methods. The affinity of the histones with a variety of DNA structures will be examined and to some extent the structures of the histones and DNA in the complexes will be determined. Comparison of the affinity of the various histone variants with DNA structures will establish the relationship between the structures of histones and their affinity for DNA. The interaction of histones with DNA structures is an important subject for study because of the potential importance of DNA:histone complexes in controlling the function, development, and maturation of living cells.
