1i0f
From Proteopedia
(New page: 200px<br /><applet load="1i0f" size="450" color="white" frame="true" align="right" spinBox="true" caption="1i0f, resolution 1.6Å" /> '''1.6 A STRUCTURE OF TH...) |
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| - | [[Image:1i0f.gif|left|200px]]<br /><applet load="1i0f" size=" | + | [[Image:1i0f.gif|left|200px]]<br /><applet load="1i0f" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1i0f, resolution 1.6Å" /> | caption="1i0f, resolution 1.6Å" /> | ||
'''1.6 A STRUCTURE OF THE A-DECAMER GCGTATACGC WITH A SINGLE 2'-O-AMINOOXYETHYL THYMINE IN PLACE OF T6, BA-FORM'''<br /> | '''1.6 A STRUCTURE OF THE A-DECAMER GCGTATACGC WITH A SINGLE 2'-O-AMINOOXYETHYL THYMINE IN PLACE OF T6, BA-FORM'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The observation of light metal ions in nucleic acids crystals is generally | + | The observation of light metal ions in nucleic acids crystals is generally a fortuitous event. Sodium ions in particular are notoriously difficult to detect because their X-ray scattering contributions are virtually identical to those of water and Na(+.)O distances are only slightly shorter than strong hydrogen bonds between well-ordered water molecules. We demonstrate here that replacement of Na(+) by K(+), Rb(+) or Cs(+) and precise measurements of anomalous differences in intensities provide a particularly sensitive method for detecting alkali metal ion-binding sites in nucleic acid crystals. Not only can alkali metal ions be readily located in such structures, but the presence of Rb(+) or Cs(+) also allows structure determination by the single wavelength anomalous diffraction technique. Besides allowing identification of high occupancy binding sites, the combination of high resolution and anomalous diffraction data established here can also pinpoint binding sites that feature only partial occupancy. Conversely, high resolution of the data alone does not necessarily allow differentiation between water and partially ordered metal ions, as demonstrated with the crystal structure of a DNA duplex determined to a resolution of 0.6 A. |
==About this Structure== | ==About this Structure== | ||
| - | 1I0F is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with BA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1I0F is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=BA:'>BA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I0F OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Egli, M.]] | [[Category: Egli, M.]] | ||
[[Category: Howard, A.]] | [[Category: Howard, A.]] | ||
| - | [[Category: Maier, M | + | [[Category: Maier, M A.]] |
[[Category: Manoharan, M.]] | [[Category: Manoharan, M.]] | ||
[[Category: Minasov, G.]] | [[Category: Minasov, G.]] | ||
| - | [[Category: Prakash, T | + | [[Category: Prakash, T P.]] |
[[Category: Tereshko, V.]] | [[Category: Tereshko, V.]] | ||
[[Category: Wawrzak, Z.]] | [[Category: Wawrzak, Z.]] | ||
| - | [[Category: Wilds, C | + | [[Category: Wilds, C J.]] |
[[Category: BA]] | [[Category: BA]] | ||
[[Category: a-form double helix]] | [[Category: a-form double helix]] | ||
[[Category: modified sugar]] | [[Category: modified sugar]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:06:41 2008'' |
Revision as of 11:06, 21 February 2008
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1.6 A STRUCTURE OF THE A-DECAMER GCGTATACGC WITH A SINGLE 2'-O-AMINOOXYETHYL THYMINE IN PLACE OF T6, BA-FORM
Overview
The observation of light metal ions in nucleic acids crystals is generally a fortuitous event. Sodium ions in particular are notoriously difficult to detect because their X-ray scattering contributions are virtually identical to those of water and Na(+.)O distances are only slightly shorter than strong hydrogen bonds between well-ordered water molecules. We demonstrate here that replacement of Na(+) by K(+), Rb(+) or Cs(+) and precise measurements of anomalous differences in intensities provide a particularly sensitive method for detecting alkali metal ion-binding sites in nucleic acid crystals. Not only can alkali metal ions be readily located in such structures, but the presence of Rb(+) or Cs(+) also allows structure determination by the single wavelength anomalous diffraction technique. Besides allowing identification of high occupancy binding sites, the combination of high resolution and anomalous diffraction data established here can also pinpoint binding sites that feature only partial occupancy. Conversely, high resolution of the data alone does not necessarily allow differentiation between water and partially ordered metal ions, as demonstrated with the crystal structure of a DNA duplex determined to a resolution of 0.6 A.
About this Structure
1I0F is a Protein complex structure of sequences from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Detection of alkali metal ions in DNA crystals using state-of-the-art X-ray diffraction experiments., Tereshko V, Wilds CJ, Minasov G, Prakash TP, Maier MA, Howard A, Wawrzak Z, Manoharan M, Egli M, Nucleic Acids Res. 2001 Mar 1;29(5):1208-15. PMID:11222771
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