1HQ3

CRYSTAL STRUCTURE OF THE HISTONE-CORE-OCTAMER IN KCL/PHOSPHATE

Summary for 1HQ3

• Entry DOI: 10.2210/pdb1hq3/pdb
• Descriptor: HISTONE H2A-IV, HISTONE H2B, HISTONE H3, ... (7 entities in total)
• Functional Keywords: histone-core octamer, nucleosome, chromatin, structural elements, histone-tail guide helices, tether structures, cl and phosphate ions, waters, dna binding protein
• Biological source: Gallus gallus (chicken); More
• Cellular location: Nucleus: P02263 P84229 P62801
• Total number of polymer chains: 8
• Total formula weight: 110731.10

Authors

Chantalat, L.,Nicholson, J.M.,Lambert, S.J.,Reid, A.J.,Donovan, M.J.,Reynolds, C.D.,Wood, C.M.,Baldwin, J.P. (deposition date: 2000-12-14, release date: 2001-01-24, Last modification date: 2023-08-09)

Primary citation

Chantalat, L.,Nicholson, J.M.,Lambert, S.J.,Reid, A.J.,Donovan, M.J.,Reynolds, C.D.,Wood, C.M.,Baldwin, J.P.
Structure of the histone-core octamer in KCl/phosphate crystals at 2.15 A resolution.
Acta Crystallogr.,Sect.D, 59:1395-1407, 2003

PubMed Abstract: The structure of the native chicken histone octamer, crystallized in 2 M KCl, 1.35 M potassium phosphate pH 6.9, has been refined at 2.15 A resolution to a final R factor of 21.4% and an R(free) of 25.2%. Unique crystal-packing interactions between histone-core octamers are strong and one of them (area 4000 A(2)) involves two chloride ions and direct interactions between six acidic amino-acid residues on one octamer and the equivalent number of basic residues on the next. These interactions are on the structured part of the octamer (not involving tails). Five phosphate ions, 23 chloride ions and 437 water molecules have been identified in the structure. The phosphate and some chloride ions bind to basic amino-acid residues that interact with DNA in the nucleosome. The binding of most of the anions and the packing interactions are unique to these crystals. In other respects, and including the positions of four chloride ions, the octamer structure is very close to that of octamers in nucleosome-core particle crystals, particularly with respect to 'docking' sequences of the histone H2As and H4s. These sequences together with the H2B-H4 four-helix bundles stabilize the histone structure in the nucleosome and prevent the dissociation of the (H2A-H2B) dimers from the (H3-H4)(2) tetramer. Possible reasons why this happens at high salt in the absence of DNA are given.

PubMed: 12876341
DOI: 10.1107/S0907444903011880

Experimental method

X-RAY DIFFRACTION (2.15 Å)