In vitro recognition of DNA base pairs by histones in histone-DNA complexes and reconstituted core Particles: an ultraviolet resonance Raman study

摘要

Resonance Raman spectra of complexes between DNA and the four core histones, alone or associated, have ben investigated in vitro using excitations at 300 and 257 nm, which give complementary informations about the DNA bases. H2A and H2B fractions recognize the G-C base pairs, while H3 and H4 (arginine rich fractions) recognize the A-T base pairs. The associated fractions from complexes with DNA which yield about the same DNA spectral modifications as the DNA-H4 complexes. This reveals the important role of the arginine rich fractions in the core particle formation and confirms the preferential in vitro assembly of nucleosome cores on A-T rich regions of ENA (25).