title: Characterization of the interaction between HMGB1 and H3-a possible means of positioning HMGB1 in chromatin.
abstract: High mobility group protein B1 (HMGB1) binds to the internucleosomal linker DNA in chromatin and abuts the nucleosome. Bending and untwisting of the linker DNA results in transmission of strain to the nucleosome core, disrupting histone/DNA contacts. An interaction between H3 and HMGB1 has been reported. Here we confirm and characterize the interaction of HMGB1 with H3, which lies close to the DNA entry/exit points around the nucleosome dyad, and may be responsible for positioning of HMGB1 on the linker DNA. We show that the interaction is between the N-terminal unstructured tail of H3 and the C-terminal unstructured acidic tail of HMGB1, which are presumably displaced from DNA and the HMG boxes, respectively, in the HMGB1-nucleosome complex. We have characterized the interaction by nuclear magnetic resonance spectroscopy and show that it is extensive for both peptides, and appears not to result in the acquisition of significant secondary structure by either partner.
authors.affiliation: Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Watson
authors.forename: Katherine
authors.initials: K
authors.lastname: Stott
authors.forename: Harry
authors.initials: H
authors.lastname: Fischl
authors.forename: Laura
authors.initials: L
authors.lastname: Cato
authors.forename: Jean O
authors.initials: JO
authors.lastname: Thomas
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D024243:HMGB1 Protein / Q000737:chemistry* / Q000378:metabolism; D006657:Histones / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002843:Chromatin; D024243:HMGB1 Protein; D006657:Histones; D004247:DNA