1hq3
From Proteopedia
(New page: 200px<br /><applet load="1hq3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1hq3, resolution 2.15Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1hq3.gif|left|200px]]<br /><applet load="1hq3" size=" | + | [[Image:1hq3.gif|left|200px]]<br /><applet load="1hq3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1hq3, resolution 2.15Å" /> | caption="1hq3, resolution 2.15Å" /> | ||
'''CRYSTAL STRUCTURE OF THE HISTONE-CORE-OCTAMER IN KCL/PHOSPHATE'''<br /> | '''CRYSTAL STRUCTURE OF THE HISTONE-CORE-OCTAMER IN KCL/PHOSPHATE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the native chicken histone octamer, crystallized in 2 M | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 1HQ3 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with PO4 and CL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1HQ3 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=CL:'>CL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HQ3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Gallus gallus]] | [[Category: Gallus gallus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Baldwin, J | + | [[Category: Baldwin, J P.]] |
[[Category: Chantalat, L.]] | [[Category: Chantalat, L.]] | ||
| - | [[Category: Donovan, M | + | [[Category: Donovan, M J.]] |
| - | [[Category: Lambert, S | + | [[Category: Lambert, S J.]] |
| - | [[Category: Nicholson, J | + | [[Category: Nicholson, J M.]] |
| - | [[Category: Reid, A | + | [[Category: Reid, A J.]] |
| - | [[Category: Reynolds, C | + | [[Category: Reynolds, C D.]] |
| - | [[Category: Wood, C | + | [[Category: Wood, C M.]] |
[[Category: CL]] | [[Category: CL]] | ||
[[Category: PO4]] | [[Category: PO4]] | ||
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[[Category: waters]] | [[Category: waters]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:03:41 2008'' |
Revision as of 11:03, 21 February 2008
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CRYSTAL STRUCTURE OF THE HISTONE-CORE-OCTAMER IN KCL/PHOSPHATE
Overview
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.
About this Structure
1HQ3 is a Protein complex structure of sequences from Gallus gallus with and as ligands. Full crystallographic information is available from OCA.
Reference
Structure of the histone-core octamer in KCl/phosphate crystals at 2.15 A resolution., Chantalat L, Nicholson JM, Lambert SJ, Reid AJ, Donovan MJ, Reynolds CD, Wood CM, Baldwin JP, Acta Crystallogr D Biol Crystallogr. 2003 Aug;59(Pt 8):1395-407. Epub 2003, Jul 23. PMID:12876341
Page seeded by OCA on Thu Feb 21 13:03:41 2008
Categories: Gallus gallus | Protein complex | Baldwin, J P. | Chantalat, L. | Donovan, M J. | Lambert, S J. | Nicholson, J M. | Reid, A J. | Reynolds, C D. | Wood, C M. | CL | PO4 | Chromatin | Cl and phosphate ions | Histone-core octamer | Histone-tail guide helices | Nucleosome | Structural elements | Tether structures | Waters
