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1kb1

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(New page: 200px<br /><applet load="1kb1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kb1" /> '''SOLUTION STRUCTURE OF AN 11-MER DNA DUPLEX C...)
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[[Image:1kb1.gif|left|200px]]<br /><applet load="1kb1" size="350" color="white" frame="true" align="right" spinBox="true"
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'''SOLUTION STRUCTURE OF AN 11-MER DNA DUPLEX CONTAINING 6-THIOGUANINE OPPOSITE CYTOSINE'''<br />
'''SOLUTION STRUCTURE OF AN 11-MER DNA DUPLEX CONTAINING 6-THIOGUANINE OPPOSITE CYTOSINE'''<br />
==Overview==
==Overview==
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The incorporation of 6-thioguanine (S6G) into DNA is an essential step in, the cytotoxic activity of thiopurines. However, the structural effects of, this substitution on duplex DNA have not been fully characterized. Here, we present the solution structures of DNA duplexes containing S6G opposite, thymine (S6G.T) and opposite cytosine (S6G.C), solved by high-resolution, NMR spectroscopy and restrained molecular dynamics. The data indicate that, both duplexes adopt right-handed helical conformations with all, Watson-Crick hydrogen bonding in place. The S6G.T structures exhibit a, wobble-type base pairing at the lesion site, with thymine shifted toward, the major groove and S6G displaced toward the minor groove. Aside from the, lesion site, the helices, including the flanking base pairs, are not, highly perturbed by the presence of the lesion. Surprisingly, thermal, dependence experiments suggest greater stability in the S6G-T mismatch, than the S6G-C base pair.
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The incorporation of 6-thioguanine (S6G) into DNA is an essential step in the cytotoxic activity of thiopurines. However, the structural effects of this substitution on duplex DNA have not been fully characterized. Here, we present the solution structures of DNA duplexes containing S6G opposite thymine (S6G.T) and opposite cytosine (S6G.C), solved by high-resolution NMR spectroscopy and restrained molecular dynamics. The data indicate that both duplexes adopt right-handed helical conformations with all Watson-Crick hydrogen bonding in place. The S6G.T structures exhibit a wobble-type base pairing at the lesion site, with thymine shifted toward the major groove and S6G displaced toward the minor groove. Aside from the lesion site, the helices, including the flanking base pairs, are not highly perturbed by the presence of the lesion. Surprisingly, thermal dependence experiments suggest greater stability in the S6G-T mismatch than the S6G-C base pair.
==About this Structure==
==About this Structure==
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1KB1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1KB1 OCA].
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1KB1 is a [http://en.wikipedia.org/wiki/Protein_complex 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=1KB1 OCA].
==Reference==
==Reference==
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[[Category: Protein complex]]
[[Category: Protein complex]]
[[Category: Bohon, J.]]
[[Category: Bohon, J.]]
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[[Category: Santos, C.R.De.Los.]]
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[[Category: Santos, C R.De Los.]]
[[Category: 6-thioguanine]]
[[Category: 6-thioguanine]]
[[Category: 6tg]]
[[Category: 6tg]]
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[[Category: thiopurine]]
[[Category: thiopurine]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 25 01:03:44 2007''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:32:03 2008''

Revision as of 11:32, 21 February 2008


1kb1

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SOLUTION STRUCTURE OF AN 11-MER DNA DUPLEX CONTAINING 6-THIOGUANINE OPPOSITE CYTOSINE

Overview

The incorporation of 6-thioguanine (S6G) into DNA is an essential step in the cytotoxic activity of thiopurines. However, the structural effects of this substitution on duplex DNA have not been fully characterized. Here, we present the solution structures of DNA duplexes containing S6G opposite thymine (S6G.T) and opposite cytosine (S6G.C), solved by high-resolution NMR spectroscopy and restrained molecular dynamics. The data indicate that both duplexes adopt right-handed helical conformations with all Watson-Crick hydrogen bonding in place. The S6G.T structures exhibit a wobble-type base pairing at the lesion site, with thymine shifted toward the major groove and S6G displaced toward the minor groove. Aside from the lesion site, the helices, including the flanking base pairs, are not highly perturbed by the presence of the lesion. Surprisingly, thermal dependence experiments suggest greater stability in the S6G-T mismatch than the S6G-C base pair.

About this Structure

1KB1 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.

Reference

Structural effect of the anticancer agent 6-thioguanine on duplex DNA., Bohon J, de los Santos CR, Nucleic Acids Res. 2003 Feb 15;31(4):1331-8. PMID:12582253

Page seeded by OCA on Thu Feb 21 13:32:03 2008

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