2020  1,374
2019  1,023
2018  0,932
2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 45(2011) N 2 p. 318-326;
E.V. Chikhirzhina1*, A.M. Polyanichko2,1, E.I. Kostyleva1, V.I. Vorob'ev1,2

Structure of DNA Complexes with Chromosomal Protein HMGB1 and Histone H1 in the Presence of Manganese Ions: 1. Circular Dichroism Spectroscopy

1Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064 Russia
2Department of Physics, St. Petersburg State University, St. Petersburg, 198905 Russia

Received - 2010-06-11; Accepted - 2010-07-07

Mechanisms of interaction of DNA with nonhistone chromosomal protein HMGB1 and linker histone H1 have been studied by means of circular dichroism and absorption spectroscopy. Both proteins are located in the internucleosomal regions of chromatin. It is demonstrated that the properties of DNA-protein complexes depend on the protein content and cannot be considered as a mere summing up of the effects of individual protein components. Interaction of the HMGB1 and H1 proteins is shown to be cooperative rather than competitive. Lysine-rich histone H1 facilitates the binding of HMGB1 to DNA by screening the negatively charged groups of the sugar-phosphate backbone of DNA and dicarboxylic amino acid residues in the C-terminal domain of HMGB1. The observed joint action of HMGB1 and H1 stimulates DNA condensation with the formation of anisotropic DNA-protein complexes with typical y-type CD spectra. Structural organization of the complexes depends not only on DNA-protein interactions but also on interaction between the HMGB1 and H1 protein molecules bound to DNA. Manganese ions significantly modify the character of interactions between components in the triple DNA-HMGB1-H1 complex. The binding of Mn2+ ions weakens DNA-protein interactions and strengthens protein-protein interactions, which promote DNA condensation and formation of large DNA-protein particles in solution.

CD spectroscopy, DNA, DNA-protein interactions, linker histone H1, manganese ions, nonhistone protein HMGB1