Physical studies of nucleosome assembly

Publisher Website
Google Scholar
Abstract
Biochemical, spectroscopic and hydrodynamic studies were performed on the reconstituted complex of 140 base pair DNA and the arginine-rich histone tetramer (H3/H4)2 from calf thymus. The histones bind to DNA in a 1:1 molar ratio to form a stable particle which orients in an electric field with a rotational correlation time of 6.3 .mu.s and a limiting reduced dichroism of -0.74. The complex was modeled hydrodynamically as a cylinder of dimensions 450 .times. 80 .times. 80 .ANG. containing approximately 1.5 superhelical turns. Addition of the lysine-rich histones to this complex causes a condensation of the structure and results in physical properties nearly identical with those of a native nucleosomal particle.