[Structural organization of DNA complexes with proteins HMGB1 and HMGB1-(A+B)].

The interaction between DNA and the nonhistone proteins HMGB1 and HMGB1-(A+B) has been studied using circular dichroism and scanning force microscopy. The recombinant protein HMGB1-(A+B) has no negatively charged C-terminal domain characteristic for HMGB1. Our earlier suggestion about the structural interaction of tandem HMGB1-domains of the recombinant protein with DNA was confirmed. It was shown that the C-terminal part modulates the interactions of HMGB1-domains with DNA. Without the C-terminal sequence, the HMGB1-(A+B) protein forms DNA-protein complexes with the ordered supramolecular structure.