1d41: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1d41.jpg|left|200px]] | [[Image:1d41.jpg|left|200px]] | ||
'''STABILIZATION OF Z-DNA BY DEMETHYLATION OF THYMINE BASES: 1.3 ANGSTROMS SINGLE-CRYSTAL STRUCTURE OF D(M5CGUAM5CG)''' | {{Structure | ||
|PDB= 1d41 |SIZE=350|CAPTION= <scene name='initialview01'>1d41</scene>, resolution 1.300Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''STABILIZATION OF Z-DNA BY DEMETHYLATION OF THYMINE BASES: 1.3 ANGSTROMS SINGLE-CRYSTAL STRUCTURE OF D(M5CGUAM5CG)''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
1D41 is a [ | 1D41 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=1D41 OCA]. | ||
==Reference== | ==Reference== | ||
Stabilization of Z-DNA by demethylation of thymine bases: 1.3-A single-crystal structure of d(m5CGUAm5CG)., Zhou GW, Ho PS, Biochemistry. 1990 Aug 7;29(31):7229-36. PMID:[http:// | Stabilization of Z-DNA by demethylation of thymine bases: 1.3-A single-crystal structure of d(m5CGUAm5CG)., Zhou GW, Ho PS, Biochemistry. 1990 Aug 7;29(31):7229-36. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/2207101 2207101] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Ho, P S.]] | [[Category: Ho, P S.]] | ||
| Line 19: | Line 28: | ||
[[Category: z-dna]] | [[Category: z-dna]] | ||
''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 10:32:36 2008'' | ||
Revision as of 11:32, 20 March 2008
| |||||||
| , resolution 1.300Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STABILIZATION OF Z-DNA BY DEMETHYLATION OF THYMINE BASES: 1.3 ANGSTROMS SINGLE-CRYSTAL STRUCTURE OF D(M5CGUAM5CG)
OverviewOverview
Methylation of cytosine bases at the C5 position has been known to stabilize Z-DNA. We had previously predicted from calculations of solvent-accessible surfaces that the methyl group at the same position of thymine has a destabilizing effect on Z-DNA. In the current studies, the sequence d(m5CGUAm5CG) has been crystallized and its structure solved as Z-DNA to 1.3-A resolution. A well-defined octahedral hexaaquomagnesium complex was observed to bridge the O4 oxygens of the adjacent uridine bases at the major groove surface, and four well-structured water molecules were found in the minor groove crevice at the d(UA) dinucleotide. These solvent interactions were not observed in the previously published Z-DNA structure of the analogous d(m5CGTAm5CG) sequence. A comparison of the thymine and uridine structures supports our prediction that demethylation of thymine bases helps to stabilize Z-DNA. A comparison of this d(UA)-containing Z-DNA structure with the analogous d(TA) structure shows that access of the O4 position is hindered by the C5 methyl of thymine due to steric and hydrophobic inhibition. In the absence of the methyl group, a magnesium-water complex binds to and slightly affects the structure of the Z-DNA major groove surface. This perturbation of the solvent structure at the major groove surface is translated into a much larger 1.41-A widening of the minor groove crevice, thereby allowing the specific binding of two water molecules at well-defined sites of each internal d(UA) base pair. Possible mechanisms by which modifications at the major groove surface of Z-DNA can affect the solvent properties of the minor groove crevice are discussed.
About this StructureAbout this Structure
1D41 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Stabilization of Z-DNA by demethylation of thymine bases: 1.3-A single-crystal structure of d(m5CGUAm5CG)., Zhou GW, Ho PS, Biochemistry. 1990 Aug 7;29(31):7229-36. PMID:2207101
Page seeded by OCA on Thu Mar 20 10:32:36 2008