1d48
From Proteopedia
(New page: 200px<br /><applet load="1d48" size="450" color="white" frame="true" align="right" spinBox="true" caption="1d48, resolution 1.000Å" /> '''STRUCTURE OF THE PU...) |
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| - | [[Image:1d48.gif|left|200px]]<br /><applet load="1d48" size=" | + | [[Image:1d48.gif|left|200px]]<br /><applet load="1d48" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1d48, resolution 1.000Å" /> | caption="1d48, resolution 1.000Å" /> | ||
'''STRUCTURE OF THE PURE-SPERMINE FORM OF Z-DNA (MAGNESIUM FREE) AT 1 ANGSTROM RESOLUTION'''<br /> | '''STRUCTURE OF THE PURE-SPERMINE FORM OF Z-DNA (MAGNESIUM FREE) AT 1 ANGSTROM RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We describe the three-dimensional X-ray structure of a complex of spermine | + | We describe the three-dimensional X-ray structure of a complex of spermine bound to a Z-DNA duplex, [d(CGCGCG)]2, in the absence of any inorganic polyvalent cations. We have crystallized the DNA hexamer d(CGCGCG) in the exclusion of magnesium and other polyvalent ions and solved its structure at 1.0-A resolution. In the crystal of this pure-spermine form of Z-DNA, the relative orientation, position, and interactions of the DNA differ from the arrangement uniformly observed in over a dozen previously reported Z-DNA hexamers. Moreover, the conformation of the Z-DNA hexamer in this structure varies somewhat from those found in earlier structures. The DNA is compressed along the helical axis, the base pairs are shifted into the major groove, and the minor groove is more narrow. The packing of spermine-DNA complexes in crystals suggests that the molecular basis for the tendency of spermine to stabilize compact DNA structures derives from the capacity of spermine to interact simultaneously with several duplexes. This capacity is maximized by both the polymorphic nature and the length of the spermine cation. The length and flexibility of spermine and the dispersion of charge-charge, hydrogen-bonding, and hydrophobic bonding potential throughout the molecule maximize the ability of spermine to interact simultaneously with different DNA molecules. |
==About this Structure== | ==About this Structure== | ||
| - | 1D48 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with SPM as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1D48 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=SPM:'>SPM</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D48 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Gao, Q.]] | [[Category: Gao, Q.]] | ||
[[Category: Rich, A.]] | [[Category: Rich, A.]] | ||
| - | [[Category: Williams, L | + | [[Category: Williams, L D.]] |
[[Category: SPM]] | [[Category: SPM]] | ||
[[Category: double helix]] | [[Category: double helix]] | ||
[[Category: z-dna]] | [[Category: z-dna]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:12:49 2008'' |
Revision as of 10:12, 21 February 2008
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STRUCTURE OF THE PURE-SPERMINE FORM OF Z-DNA (MAGNESIUM FREE) AT 1 ANGSTROM RESOLUTION
Overview
We describe the three-dimensional X-ray structure of a complex of spermine bound to a Z-DNA duplex, [d(CGCGCG)]2, in the absence of any inorganic polyvalent cations. We have crystallized the DNA hexamer d(CGCGCG) in the exclusion of magnesium and other polyvalent ions and solved its structure at 1.0-A resolution. In the crystal of this pure-spermine form of Z-DNA, the relative orientation, position, and interactions of the DNA differ from the arrangement uniformly observed in over a dozen previously reported Z-DNA hexamers. Moreover, the conformation of the Z-DNA hexamer in this structure varies somewhat from those found in earlier structures. The DNA is compressed along the helical axis, the base pairs are shifted into the major groove, and the minor groove is more narrow. The packing of spermine-DNA complexes in crystals suggests that the molecular basis for the tendency of spermine to stabilize compact DNA structures derives from the capacity of spermine to interact simultaneously with several duplexes. This capacity is maximized by both the polymorphic nature and the length of the spermine cation. The length and flexibility of spermine and the dispersion of charge-charge, hydrogen-bonding, and hydrophobic bonding potential throughout the molecule maximize the ability of spermine to interact simultaneously with different DNA molecules.
About this Structure
1D48 is a Protein complex structure of sequences from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of the pure-spermine form of Z-DNA (magnesium free) at 1-A resolution., Egli M, Williams LD, Gao Q, Rich A, Biochemistry. 1991 Dec 3;30(48):11388-402. PMID:1742278
Page seeded by OCA on Thu Feb 21 12:12:49 2008
Categories: Protein complex | Egli, M. | Gao, Q. | Rich, A. | Williams, L D. | SPM | Double helix | Z-dna
