2aro

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spinqualitylabelsall models 2aro, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

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

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