title: The conformation of histone H5 bound to DNA. Maintenance of the globular structure after binding.
abstract: Trypsin digestion is used to investigate the conformation of histone H5 when bound to DNA. A central region of H5 comprising residues (22--100) is found to be resistant to digestion and it is concluded that this region is compacted whilst the remaining N- and C-terminal regions are more extended. Since this is the same result found previously for the free solution conformation of histone H5 it follows that a 3-domain structure is preserved on DNA binding. The binding of H5 and the central region (22--100) to DNA is also studied using proton magnetic resonance (270 MHz) and a precipitation approach. It is concluded that all 3 domains of H5 bind to DNA at low ionic strengths. The central domain (residues 22--100) is released at 0.3--0.4 M NaCl, but 0.7 M NaCl is required to release the N- and C-terminal regions. Comparison is made of H5 binding to DNA with that of the related histone H1.
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D004247:DNA; D004912:Erythrocytes; D006657:Histones; D009682:Magnetic Resonance Spectroscopy; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D011487:Protein Conformation; D012995:Solubility
chemical_list: D006657:Histones; D010446:Peptide Fragments; D004247:DNA