Open AccessCharacterization of the histone core complex.
Author(s) -
Su-Yun Chung,
Walter E. Hill,
Paul Doty
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.4.1680
Subject(s) - histone octamer , tetramer , sedimentation equilibrium , sedimentation coefficient , chemistry , histone , ultracentrifuge , crystallography , histone h1 , biophysics , biochemistry , biology , nucleosome , dna , enzyme
A stable histone core complex containing equimolar ratios of H2A, H2B, H3, and H4 has been isolated from chicken erythrocyte chromatin in high salt. This complex has been characterized by sedimentation and chemical cross-linking studies. In velocity ultracentrifugation, only one single sharp sedimentation boundary has been observed with sedimentation coefficient S020,w = 3.8 +/- 0.1. The molecular weight of the histone core complex has been investigated by low-speed sedimentation equilibrium studies over a wide range of protein concentration. Analysis of the apparent weight-average molecular weight as a function of concentration indicates that the histone core complex in 2 M NaCl, pH 9.0, is in equilibrium between a tetramer (H2A)(H2B)(H3)(H4) and an octamer [(H2A)(H2B)(H3)(H4)]2 species with a tetramer molecular weight of 55,000. The equilibrium constant K is approximately 1.2 X 10(-5) liter per mol at 10 degrees. Evidence of such a tetramer-octamer equilibrium in solution is also supported by the results of our chemical crosslinking experiments on the histone core complex.