1rqy
From Proteopedia
(New page: 200px<br /><applet load="1rqy" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rqy, resolution 1.55Å" /> '''9-amino-[N-(2-dimeth...) |
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| - | [[Image:1rqy.gif|left|200px]]<br /><applet load="1rqy" size=" | + | [[Image:1rqy.gif|left|200px]]<br /><applet load="1rqy" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1rqy, resolution 1.55Å" /> | caption="1rqy, resolution 1.55Å" /> | ||
'''9-amino-[N-(2-dimethylamino)proply]-acridine-4-carboxamide bound to d(CGTACG)2'''<br /> | '''9-amino-[N-(2-dimethylamino)proply]-acridine-4-carboxamide bound to d(CGTACG)2'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the complex formed between | + | The structure of the complex formed between 9-amino-[N-(2-dimethylamino)propyl]acridine-4-carboxamide and d(CGTACG)(2) has been refined to a resolution of 1.55 A. The complex crystallized in space group C222. An asymmetric unit comprises two strands of DNA, one disordered drug molecule, two cobalt(II) ions, two magnesium ions and 32 water molecules. The DNA helices stack in continuous columns, with their four central base pairs adopting a B-like motif. The terminal G.C base pairs engage in different interactions. At one end of the duplex there is a CpG dinucleotide overlap modified by ligand intercalation and terminal cytosine exchange between symmetry-related duplexes. An intercalation complex is formed involving four DNA duplexes, four disordered ligand molecules and two pairs of base tetrads. The other end of the DNA is frayed, with the terminal guanine lying in the minor groove of the next duplex in the column. The structure is stabilized by guanine N7-cobalt(II) coordination. The structure is compared with previously published isomorphous structures of d(CGTACG)(2) complexed with intercalators in the presence of cobalt and it is concluded that the formation of this crystal form is primarily determined by DNA-DNA interactions and packing forces, rather than by special interactions between the ligand and the DNA. Given the nature of the ligands found in these complexes, the relevance of the quadruplex structure to the biological activity of those agents, known to be topoisomerase poisons, is questioned. |
==About this Structure== | ==About this Structure== | ||
| - | 1RQY is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with CO, MG and 7AD as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1RQY is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=CO:'>CO</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=7AD:'>7AD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RQY OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Adams, A.]] | [[Category: Adams, A.]] | ||
| - | [[Category: Denny, W | + | [[Category: Denny, W A.]] |
| - | [[Category: Guss, J | + | [[Category: Guss, J M.]] |
| - | [[Category: Wakelin, L | + | [[Category: Wakelin, L P.]] |
[[Category: 7AD]] | [[Category: 7AD]] | ||
[[Category: CO]] | [[Category: CO]] | ||
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[[Category: unusual intercalation]] | [[Category: unusual intercalation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:53:42 2008'' |
Revision as of 12:53, 21 February 2008
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9-amino-[N-(2-dimethylamino)proply]-acridine-4-carboxamide bound to d(CGTACG)2
Overview
The structure of the complex formed between 9-amino-[N-(2-dimethylamino)propyl]acridine-4-carboxamide and d(CGTACG)(2) has been refined to a resolution of 1.55 A. The complex crystallized in space group C222. An asymmetric unit comprises two strands of DNA, one disordered drug molecule, two cobalt(II) ions, two magnesium ions and 32 water molecules. The DNA helices stack in continuous columns, with their four central base pairs adopting a B-like motif. The terminal G.C base pairs engage in different interactions. At one end of the duplex there is a CpG dinucleotide overlap modified by ligand intercalation and terminal cytosine exchange between symmetry-related duplexes. An intercalation complex is formed involving four DNA duplexes, four disordered ligand molecules and two pairs of base tetrads. The other end of the DNA is frayed, with the terminal guanine lying in the minor groove of the next duplex in the column. The structure is stabilized by guanine N7-cobalt(II) coordination. The structure is compared with previously published isomorphous structures of d(CGTACG)(2) complexed with intercalators in the presence of cobalt and it is concluded that the formation of this crystal form is primarily determined by DNA-DNA interactions and packing forces, rather than by special interactions between the ligand and the DNA. Given the nature of the ligands found in these complexes, the relevance of the quadruplex structure to the biological activity of those agents, known to be topoisomerase poisons, is questioned.
About this Structure
1RQY is a Protein complex structure of sequences from [1] with , and as ligands. Full crystallographic information is available from OCA.
Reference
Structure of 9-amino-[N-(2-dimethylamino)propyl]acridine-4-carboxamide bound to d(CGTACG)(2): a comparison of structures of d(CGTACG)(2) complexed with intercalatorsin the presence of cobalt., Adams A, Guss JM, Denny WA, Wakelin LP, Acta Crystallogr D Biol Crystallogr. 2004 May;60(Pt 5):823-8. Epub 2004, Apr 21. PMID:15103127
Page seeded by OCA on Thu Feb 21 14:53:42 2008
Categories: Protein complex | Adams, A. | Denny, W A. | Guss, J M. | Wakelin, L P. | 7AD | CO | MG | Acridine | B-dna | Cytosine exchange | Quadruplex | Unusual intercalation
