Analysis of the secondary structure of chromatin linker proteins HMGB1, H1 and their complexes

Abstract

The nonhistone chromosomal protein HMGB1 and histone H1 are chromatin linker proteins. The functions of linker proteins are closely related to their conformational state. Currently, the structure of proteins that play a key role in the formation of higher levels of chromatin structural organization is being actively studied. In this work, a comparative analysis of the secondary structure of the linker histone H1 and the nonhistone protein HMGB1 was carried out. By using UV-circular dichroism and FTIR spectroscopy it was shown that the positively charged histone H1 binds to the C-terminal fragment of HMGB1, stabilizing the resulting complex and inducing the formation of additional a-helical regions in both proteins.