Determinants of Specific Binding of HMGB1 Protein to Hemicatenated DNA Loops

Protein HMGB1 has long been known as one of the most abundant non-histone proteins in the nucleus of mammalian cells, and has regained interest recently for its function as an extracellular cytokine. As a DNA-binding protein, HMGB1 facilitates DNA–protein interactions by increasing the flexibility o...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of molecular biology 2005-11, Vol.353 (4), p.822-837
Hauptverfasser: Jaouen, Sandrine, de Koning, Leanne, Gaillard, Claire, Muselíková-Polanská, Eva, Štros, Michal, Strauss, François
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Protein HMGB1 has long been known as one of the most abundant non-histone proteins in the nucleus of mammalian cells, and has regained interest recently for its function as an extracellular cytokine. As a DNA-binding protein, HMGB1 facilitates DNA–protein interactions by increasing the flexibility of the double helix, and binds specifically to distorted DNA structures. We have previously observed that HMGB1 binds with extremely high affinity to a novel DNA structure, hemicatenated DNA loops (hcDNA), in which double-stranded DNA fragments containing a tract of poly(CA)·poly(TG) form a loop maintained at its base by a hemicatenane. Here, we show that the single HMGB1 domains A and B, the HMG-box domain of sex determination factor SRY, as well as the prokaryotic HMGB1-like protein HU, specifically interact with hcDNA ( K d∼0.5 nM). However, the affinity of full-length HMGB1 for hcDNA is three orders of magnitude higher ( K d
ISSN:0022-2836
1089-8638
DOI:10.1016/j.jmb.2005.08.073