146d
From Proteopedia
(New page: 200px<br /><applet load="146d" size="450" color="white" frame="true" align="right" spinBox="true" caption="146d" /> '''SOLUTION STRUCTURE OF THE MITHRAMYCIN DIMER-...) |
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'''SOLUTION STRUCTURE OF THE MITHRAMYCIN DIMER-DNA COMPLEX'''<br /> | '''SOLUTION STRUCTURE OF THE MITHRAMYCIN DIMER-DNA COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We have characterized the NMR parameters for the complexes formed by the | + | We have characterized the NMR parameters for the complexes formed by the Mg(2+)-coordinated mithramycin dimer with self-complementary d(T-G-G-C-C-A) and d(T-C-G-C-G-A) duplexes. The solution structure of the latter complex has been determined using a combined NMR-molecular dynamics study including relaxation matrix refinement. The Mg(2+)-coordinated mithramycin dimer-d(T-C-G-C-G-A) complex exhibits a 2-fold center of symmetry with the divalent cation coordinated aglycons positioned opposite the central (G3-C4).(G3-C4) segment such that the aglycon C8 hydroxyl oxygens form symmetrical sequence-specific hydrogen bonds to guanine amino protons in the complex. The C-D-E trisaccharide segments of each monomer in the mithramycin dimer adopt extended conformations, are positioned inside the minor groove, and are directed toward either end of the duplex. The C-D saccharide component of one monomer and the aglycon of the other monomer in the mithramycin dimer share a widened minor groove with the hydrophobic edges of the C and D sugars interacting with individual strands of the duplex. The E-sugar ring is positioned in the floor of the minor groove, and its hydroxyl-bearing face interacts with both strands of the duplex through hydrogen-bonding and hydrophobic intermolecular interactions. The A-B disaccharide and the hydrophilic side chain form intermolecular contacts with the sugar-phosphate backbone in the complex. The antiparallel alignment of divalent cation coordinated monomers in the mithramycin dimer results in the two outwardly directed C-D-E trisaccharide segments generating a right-handed continuous hexasaccharide domain that spans six base pairs in the minor groove of the duplex. The solution structure of the mithramycin dimer-DNA complex reported in this study and the solution structure of the chromomycin dimer-DNA complex reported previously [Gao, X., Mirau, P., & Patel, D. J. (1992) J. Mol. Biol. 223, 259-279] show global similarities, as well as local differences that are of interest. All four nucleotides in the tetranucleotide segment of the duplex centered about the sequence-specific (G-C).(G-C) step adopt A-DNA sugar puckers and glycosidic torsion angles in the chromomycin dimer-DNA complex, while only the central cytidine adopts an A-DNA sugar pucker and glycosidic torsion angle in the mithramycin dimer-DNA complex.(ABSTRACT TRUNCATED AT 400 WORDS) |
==About this Structure== | ==About this Structure== | ||
| - | 146D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with MG, CRH and MDA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 146D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=CRH:'>CRH</scene> and <scene name='pdbligand=MDA:'>MDA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=146D OCA]. |
==Reference== | ==Reference== | ||
Solution structure of the mithramycin dimer-DNA complex., Sastry M, Patel DJ, Biochemistry. 1993 Jul 6;32(26):6588-604. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8329387 8329387] | Solution structure of the mithramycin dimer-DNA complex., Sastry M, Patel DJ, Biochemistry. 1993 Jul 6;32(26):6588-604. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8329387 8329387] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Patel, D | + | [[Category: Patel, D J.]] |
[[Category: Sastry, M.]] | [[Category: Sastry, M.]] | ||
[[Category: CRH]] | [[Category: CRH]] | ||
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[[Category: nmr]] | [[Category: nmr]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:38:17 2008'' |
Revision as of 09:38, 21 February 2008
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SOLUTION STRUCTURE OF THE MITHRAMYCIN DIMER-DNA COMPLEX
Overview
We have characterized the NMR parameters for the complexes formed by the Mg(2+)-coordinated mithramycin dimer with self-complementary d(T-G-G-C-C-A) and d(T-C-G-C-G-A) duplexes. The solution structure of the latter complex has been determined using a combined NMR-molecular dynamics study including relaxation matrix refinement. The Mg(2+)-coordinated mithramycin dimer-d(T-C-G-C-G-A) complex exhibits a 2-fold center of symmetry with the divalent cation coordinated aglycons positioned opposite the central (G3-C4).(G3-C4) segment such that the aglycon C8 hydroxyl oxygens form symmetrical sequence-specific hydrogen bonds to guanine amino protons in the complex. The C-D-E trisaccharide segments of each monomer in the mithramycin dimer adopt extended conformations, are positioned inside the minor groove, and are directed toward either end of the duplex. The C-D saccharide component of one monomer and the aglycon of the other monomer in the mithramycin dimer share a widened minor groove with the hydrophobic edges of the C and D sugars interacting with individual strands of the duplex. The E-sugar ring is positioned in the floor of the minor groove, and its hydroxyl-bearing face interacts with both strands of the duplex through hydrogen-bonding and hydrophobic intermolecular interactions. The A-B disaccharide and the hydrophilic side chain form intermolecular contacts with the sugar-phosphate backbone in the complex. The antiparallel alignment of divalent cation coordinated monomers in the mithramycin dimer results in the two outwardly directed C-D-E trisaccharide segments generating a right-handed continuous hexasaccharide domain that spans six base pairs in the minor groove of the duplex. The solution structure of the mithramycin dimer-DNA complex reported in this study and the solution structure of the chromomycin dimer-DNA complex reported previously [Gao, X., Mirau, P., & Patel, D. J. (1992) J. Mol. Biol. 223, 259-279] show global similarities, as well as local differences that are of interest. All four nucleotides in the tetranucleotide segment of the duplex centered about the sequence-specific (G-C).(G-C) step adopt A-DNA sugar puckers and glycosidic torsion angles in the chromomycin dimer-DNA complex, while only the central cytidine adopts an A-DNA sugar pucker and glycosidic torsion angle in the mithramycin dimer-DNA complex.(ABSTRACT TRUNCATED AT 400 WORDS)
About this Structure
146D is a Protein complex structure of sequences from [1] with , and as ligands. Full crystallographic information is available from OCA.
Reference
Solution structure of the mithramycin dimer-DNA complex., Sastry M, Patel DJ, Biochemistry. 1993 Jul 6;32(26):6588-604. PMID:8329387
Page seeded by OCA on Thu Feb 21 11:38:17 2008
Categories: Protein complex | Patel, D J. | Sastry, M. | CRH | MDA | MG | Dna | Mithramycin dimer | Nmr
