1a8w
From Proteopedia
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| - | [[Image:1a8w.gif|left|200px]] | + | [[Image:1a8w.gif|left|200px]] |
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| - | '''A K+ CATION-INDUCED CONFORMATIONAL SWITCH WITHIN A LOOP SPANNING SEGMENT OF A DNA QUADRUPLEX CONTAINING G-G-G-C REPEATS, NMR, 8 STRUCTURES''' | + | {{Structure |
| + | |PDB= 1a8w |SIZE=350|CAPTION= <scene name='initialview01'>1a8w</scene> | ||
| + | |SITE= | ||
| + | |LIGAND= | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
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| + | '''A K+ CATION-INDUCED CONFORMATIONAL SWITCH WITHIN A LOOP SPANNING SEGMENT OF A DNA QUADRUPLEX CONTAINING G-G-G-C REPEATS, NMR, 8 STRUCTURES''' | ||
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==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1A8W is a [ | + | 1A8W is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1A8W OCA]. |
==Reference== | ==Reference== | ||
| - | A K cation-induced conformational switch within a loop spanning segment of a DNA quadruplex containing G-G-G-C repeats., Bouaziz S, Kettani A, Patel DJ, J Mol Biol. 1998 Sep 25;282(3):637-52. PMID:[http:// | + | A K cation-induced conformational switch within a loop spanning segment of a DNA quadruplex containing G-G-G-C repeats., Bouaziz S, Kettani A, Patel DJ, J Mol Biol. 1998 Sep 25;282(3):637-52. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9737927 9737927] |
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Bouaziz, S.]] | [[Category: Bouaziz, S.]] | ||
[[Category: Kettani, A.]] | [[Category: Kettani, A.]] | ||
[[Category: Patel, D J.]] | [[Category: Patel, D J.]] | ||
| - | [[Category: cation dependent conformational | + | [[Category: cation dependent conformational transition]] |
[[Category: deoxyribonucleic acid]] | [[Category: deoxyribonucleic acid]] | ||
[[Category: dna quadruplexes targeted to hiv integrase]] | [[Category: dna quadruplexes targeted to hiv integrase]] | ||
| - | [[Category: g-g-g-c repeat-containing dna | + | [[Category: g-g-g-c repeat-containing dna quadruplex]] |
| - | [[Category: k+ cation coordination | + | [[Category: k+ cation coordination site]] |
[[Category: k+ cation encapsulation within a hairpin loop]] | [[Category: k+ cation encapsulation within a hairpin loop]] | ||
[[Category: monovalent]] | [[Category: monovalent]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 09:54:36 2008'' |
Revision as of 07:54, 20 March 2008
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A K+ CATION-INDUCED CONFORMATIONAL SWITCH WITHIN A LOOP SPANNING SEGMENT OF A DNA QUADRUPLEX CONTAINING G-G-G-C REPEATS, NMR, 8 STRUCTURES
Overview
We have identified a unique structural transition (in slow exchange on the NMR time scale) in the tertiary fold of the d(G-G-G-C-T4-G-G-G-C) quadruplex on proceeding from Na+ to K+ as counterion in aqueous solution. Both monovalent cation-dependent conformations exhibit certain common structural features, which include head-to-tail dimerization of two symmetry-related stem-hairpin loops, adjacent strands which are antiparallel to each other and adjacent stacked G(syn).G(anti). G(syn).G(anti) tetrads in the central core of the quadruplexes. The Na and K cation stabilized structures of the d(G-G-G-C-T4-G-G-G-C) quadruplexes differ in the conformations of the T-T-T-T loops, the relative alignment of G.C base-pairs positioned opposite each other through their major groove edges and potentially in the number of monovalent cation binding sites. We have identified potential K cation binding cavities within the symmetry-related T-T-T-G segments, suggesting the potential for two additional monovalent cation binding sites in the K cation-stabilized quadruplex relative to its Na cation-stabilized counterpart. Modeling studies suggest that the major groove edges of guanine residues in Watson-Crick G.C base-pairs could potentially be bridged by coordinated K cations in the d(G-G-G-C-T4-G-G-G-C) quadruplex in KCl solution in contrast to formation of G.C.G.C tetrads for the corresponding quadruplex in NaCl solution. Our results defining the molecular basis of a Na to K cation-dependent conformational switch in the loop spanning segment of the d(G-G-G-C-T4-G-G-G-C) quadruplex may have relevance to recent observations that specific K cation coordinated loop conformations within quadruplexes exhibit inhibitory activity against HIV integrase.
About this Structure
1A8W is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
A K cation-induced conformational switch within a loop spanning segment of a DNA quadruplex containing G-G-G-C repeats., Bouaziz S, Kettani A, Patel DJ, J Mol Biol. 1998 Sep 25;282(3):637-52. PMID:9737927
Page seeded by OCA on Thu Mar 20 09:54:36 2008
Categories: Protein complex | Bouaziz, S. | Kettani, A. | Patel, D J. | Cation dependent conformational transition | Deoxyribonucleic acid | Dna quadruplexes targeted to hiv integrase | G-g-g-c repeat-containing dna quadruplex | K+ cation coordination site | K+ cation encapsulation within a hairpin loop | Monovalent
