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2aro
From Proteopedia
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Crystal Structure Of The Native Histone Octamer To 2.1 Angstrom Resolution, Crystalised In The Presence Of S-Nitrosoglutathione
Overview
A H3 dimer band is produced when purified native histone octamers are run, on an SDS-PAGE gel in a beta-mercaptoethanol-free environment. To, investigate this, native histone octamer crystals, derived from chicken, erythrocytes, and of structure (H2A-H2B)-(H4-H3)-(H3'-H4')-(H2B'-H2A'), were grown in 2 M KCl, 1.35 M potassium phosphates and 250-350 microM of, the oxidising agent S-nitrosoglutathione, pH 6.9. X-ray diffraction data, were acquired to 2.10 A resolution, yielding a structure with an Rwork, value of 18.6% and an Rfree of 22.5%. The space group is P6(5), the, asymmetric unit of which contains one complete octamer. Compared to the, 1.90 A resolution, unoxidised native histone octamer structure, the, crystals show a reduction of 2.5% in the c-axis of the unit cell, and, free-energy calculations reveal that the H3-H3' dimer interface in the, latter has become thermodynamically stable, in contrast to the former., Although the inter-sulphur distance of the two H3 cysteines in the, oxidised native histone octamer has reduced to 6 A from the 7 A of the, unoxidised form, analysis of the hydrogen bonds that constitute the, (H4-H3)-(H3'-H4') tetramer indicates that the formation of a disulphide, bond in the H3-H3' dimer interface is incompatible with stable tetramer, formation. The biochemical and biophysical evidence, taken as a whole, is, indicative of crystals that have a stable H3-H3' dimer interface, possibly, extending to the interface within an isolated H3-H3' dimer, observed in, SDS-PAGE gels.
About this Structure
2ARO is a Protein complex structure of sequences from Gallus gallus with PO4 and CL as ligands. Full crystallographic information is available from OCA.
Reference
The oxidised histone octamer does not form a H3 disulphide bond., Wood CM, Sodngam S, Nicholson JM, Lambert SJ, Reynolds CD, Baldwin JP, Biochim Biophys Acta. 2006 Aug;1764(8):1356-62. Epub 2006 Jul 21. PMID:16920041
Page seeded by OCA on Wed Nov 21 08:19:18 2007
Categories: Gallus gallus | Protein complex | Baldwin, J.P. | Lambert, S.J. | Nicholson, J.M. | Reynolds, C.D. | Sodngam, S. | Wood, C.M. | CL | PO4 | Allostery | Circular dichroism | Octamer | Oxidation
