Book of Abstracts: Albany 2009
June 16-20 2009
© Adenine Press (2008)
Determinants of Histone Tail Function during Chromatin Condensation
Eukaryotic DNA is bound to octamers of core histones to form nucleosomal arrays. Nucleosomal arrays complexed with linker histones or other chromosomal proteins are called chromatin fibers. Model nucleosomal arrays and chromatin fibers have been used to probe the determinants of core histone NTD and linker histone CTD function during salt-dependent array/fiber condensation. Previously we have shown that the core histone N-terminal ?tail? domains are essential mediators of the nucleosome-nucleosome interactions involved in fiber condensation, while the linker histone C-terminal domain is needed to stabilize condensed chromatin. Both the core histone NTDs and the linker histone CTD are intrinsically disordered protein domains. In the present work, site directed mutagenesis has been used to create novel core and linker histone proteins with specifically altered N- and C-terminal domains, respectively. These mutant histones have then been assembled with defined DNA templates into model nucleosomal arrays and chromatin fibers. Analytical hydrodynamic analyses of the mutant nucleosomal arrays and chromatin fibers in the presence of salts indicate have helped dissect the molecular determinants of core and linker histone tail domain function during chromatin condensation.
Jeffrey C. Hansen
Department of Biochemistry and Molecular Biology