1qkg
From Proteopedia
(New page: 200px<br /><applet load="1qkg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qkg" /> '''DNA DECAMER DUPLEX CONTAINING T-T DEWAR PHOT...) |
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| - | [[Image:1qkg.gif|left|200px]]<br /><applet load="1qkg" size=" | + | [[Image:1qkg.gif|left|200px]]<br /><applet load="1qkg" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''DNA DECAMER DUPLEX CONTAINING T-T DEWAR PHOTOPRODUCT'''<br /> | '''DNA DECAMER DUPLEX CONTAINING T-T DEWAR PHOTOPRODUCT'''<br /> | ||
==Overview== | ==Overview== | ||
| - | In contrast to the highly mutagenic pyrimidine(6-4)pyrimidone | + | In contrast to the highly mutagenic pyrimidine(6-4)pyrimidone photoproduct, its Dewar valence isomer (Dewar product) has low mutagenic potential and produces a broad range of mutations [LeClerc, J. E., Borden, A. & Lawrence, C. W. (1991) Proc. Natl. Acad. Sci. USA 88, 9685-9689]. To determine the origin of the mutagenic property of the Dewar product, we used experimental NMR restraints and molecular dynamics to determine the solution structure of a Dewar-lesion DNA decamer duplex. This DNA decamer duplex (DW/GA duplex) contains a mismatched base pair between the 3' T residue of the Dewar lesion (T6) and an opposed G residue (G15). The 3' T (T6) of the Dewar lesion formed stable hydrogen bonds with the opposing G15 residue. However, the helical bending and unwinding angles of the DW/GA duplex were much larger than those of a second duplex that contains the Dewar lesion and opposing A15 and A16 residues (DW/AA duplex). The DW/GA duplex showed poorer stacking interactions at the two bases of the Dewar product and at the adjacent A7 small middle dotT14 base pair than did the DW/AA duplex. These structural features imply that no thermal stability or conformational benefit is obtained by incorporating a G instead of an A opposite the 3' T of the Dewar lesion. These properties may thus facilitate the preferential incorporation of an A in accordance with the A rule during translesion replication and lead to the low frequency of 3' T-->C mutations observed at this site. |
==About this Structure== | ==About this Structure== | ||
| - | 1QKG 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:// | + | 1QKG 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=1QKG OCA]. |
==Reference== | ==Reference== | ||
The Dewar photoproduct of thymidylyl(3'-->5')- thymidine (Dewar product) exhibits mutagenic behavior in accordance with the "A rule"., Lee JH, Bae SH, Choi BS, Proc Natl Acad Sci U S A. 2000 Apr 25;97(9):4591-6. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10758155 10758155] | The Dewar photoproduct of thymidylyl(3'-->5')- thymidine (Dewar product) exhibits mutagenic behavior in accordance with the "A rule"., Lee JH, Bae SH, Choi BS, Proc Natl Acad Sci U S A. 2000 Apr 25;97(9):4591-6. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10758155 10758155] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Bae, S | + | [[Category: Bae, S H.]] |
| - | [[Category: Choi, B | + | [[Category: Choi, B S.]] |
| - | [[Category: Choi, Y | + | [[Category: Choi, Y J.]] |
| - | [[Category: Lee, J | + | [[Category: Lee, J H.]] |
[[Category: (6-4) adduct]] | [[Category: (6-4) adduct]] | ||
[[Category: dewar product]] | [[Category: dewar product]] | ||
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[[Category: translesion replication]] | [[Category: translesion replication]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:40:40 2008'' |
Revision as of 12:40, 21 February 2008
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DNA DECAMER DUPLEX CONTAINING T-T DEWAR PHOTOPRODUCT
Overview
In contrast to the highly mutagenic pyrimidine(6-4)pyrimidone photoproduct, its Dewar valence isomer (Dewar product) has low mutagenic potential and produces a broad range of mutations [LeClerc, J. E., Borden, A. & Lawrence, C. W. (1991) Proc. Natl. Acad. Sci. USA 88, 9685-9689]. To determine the origin of the mutagenic property of the Dewar product, we used experimental NMR restraints and molecular dynamics to determine the solution structure of a Dewar-lesion DNA decamer duplex. This DNA decamer duplex (DW/GA duplex) contains a mismatched base pair between the 3' T residue of the Dewar lesion (T6) and an opposed G residue (G15). The 3' T (T6) of the Dewar lesion formed stable hydrogen bonds with the opposing G15 residue. However, the helical bending and unwinding angles of the DW/GA duplex were much larger than those of a second duplex that contains the Dewar lesion and opposing A15 and A16 residues (DW/AA duplex). The DW/GA duplex showed poorer stacking interactions at the two bases of the Dewar product and at the adjacent A7 small middle dotT14 base pair than did the DW/AA duplex. These structural features imply that no thermal stability or conformational benefit is obtained by incorporating a G instead of an A opposite the 3' T of the Dewar lesion. These properties may thus facilitate the preferential incorporation of an A in accordance with the A rule during translesion replication and lead to the low frequency of 3' T-->C mutations observed at this site.
About this Structure
1QKG is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
The Dewar photoproduct of thymidylyl(3'-->5')- thymidine (Dewar product) exhibits mutagenic behavior in accordance with the "A rule"., Lee JH, Bae SH, Choi BS, Proc Natl Acad Sci U S A. 2000 Apr 25;97(9):4591-6. PMID:10758155
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