138d: Difference between revisions

Revision as of 12:38, 21 February 2008

A-DNA DECAMER D(GCGGGCCCGC)-HEXAGONAL CRYSTAL FORM

OverviewOverview

We have determined the structure of the A-DNA decamer d(GCGGGCCCGC) in two crystal forms, orthorhombic and hexagonal, at 1.7- and 1.8-A resolution, respectively. In the orthorhombic form, the fifth guanine residue has nearly trans-trans conformations for the alpha-gamma backbone torsions, as in the isomorphous orthorhombic structure d(CCCGGCCGGG) [Ramakrishnan, B., & Sundaralingam, M. (1993) J. Mol. Biol. 231, 431-444]. However, in the hexagonal form, the eighth cytosine residue adopts the trans-trans conformations for the backbone alpha-gamma torsions, as in the isomorphous hexagonal structure d(ACCGGCCGGT) [Frederick, C. A., Quigley, G. J., Teng, M.-K., Coll, M., van der Marel, G. A., van Boom, J. H., Rich, A., & Wang, A. H.-J. (1989) Eur. J. Biochem. 181, 295-307]. Even though the average helix and base-pair parameters are nearly the same in the two polymorphous crystal forms having the same sequence, many of the base-dependent local helix parameters are quite different. However, in the isomorphous crystal forms, in spite of the differing base sequences, the local helix and base-pair parameters of the duplexes are nearly the same. This indicates that, in crystals, the local conformation of a DNA structure is affected severely by the crystal packing environment rather than by the base sequence.

About this StructureAbout this Structure

138D is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.

ReferenceReference

Evidence for crystal environment dominating base sequence effects on DNA conformation: crystal structures of the orthorhombic and hexagonal polymorphs of the A-DNA decamer d(GCGGGCCCGC) and comparison with their isomorphous crystal structures., Ramakrishnan B, Sundaralingam M, Biochemistry. 1993 Oct 26;32(42):11458-68. PMID:8218212

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 '''A-DNA DECAMER D(GCGGGCCCGC)-HEXAGONAL CRYSTAL FORM'''<br />
 ==Overview==
-We have determined the structure of the A-DNA decamer d(GCGGGCCCGC) in two, crystal forms, orthorhombic and hexagonal, at 1.7- and 1.8-A resolution, respectively. In the orthorhombic form, the fifth guanine residue has, nearly trans-trans conformations for the alpha-gamma backbone torsions, as, in the isomorphous orthorhombic structure d(CCCGGCCGGG) [Ramakrishnan, B., &amp; Sundaralingam, M. (1993) J. Mol. Biol. 231, 431-444]. However, in the, hexagonal form, the eighth cytosine residue adopts the trans-trans, conformations for the backbone alpha-gamma torsions, as in the isomorphous, hexagonal structure d(ACCGGCCGGT) [Frederick, C. A., Quigley, G. J., Teng, M.-K., Coll, M., van der Marel, G. A., van Boom, J. H., Rich, A., &amp; Wang, A. H.-J. (1989) Eur. J. Biochem. 181, 295-307]. Even though the average, helix and base-pair parameters are nearly the same in the two polymorphous, crystal forms having the same sequence, many of the base-dependent local, helix parameters are quite different. However, in the isomorphous crystal, forms, in spite of the differing base sequences, the local helix and, base-pair parameters of the duplexes are nearly the same. This indicates, that, in crystals, the local conformation of a DNA structure is affected, severely by the crystal packing environment rather than by the base, sequence.
+We have determined the structure of the A-DNA decamer d(GCGGGCCCGC) in two crystal forms, orthorhombic and hexagonal, at 1.7- and 1.8-A resolution, respectively. In the orthorhombic form, the fifth guanine residue has nearly trans-trans conformations for the alpha-gamma backbone torsions, as in the isomorphous orthorhombic structure d(CCCGGCCGGG) [Ramakrishnan, B., &amp; Sundaralingam, M. (1993) J. Mol. Biol. 231, 431-444]. However, in the hexagonal form, the eighth cytosine residue adopts the trans-trans conformations for the backbone alpha-gamma torsions, as in the isomorphous hexagonal structure d(ACCGGCCGGT) [Frederick, C. A., Quigley, G. J., Teng, M.-K., Coll, M., van der Marel, G. A., van Boom, J. H., Rich, A., &amp; Wang, A. H.-J. (1989) Eur. J. Biochem. 181, 295-307]. Even though the average helix and base-pair parameters are nearly the same in the two polymorphous crystal forms having the same sequence, many of the base-dependent local helix parameters are quite different. However, in the isomorphous crystal forms, in spite of the differing base sequences, the local helix and base-pair parameters of the duplexes are nearly the same. This indicates that, in crystals, the local conformation of a DNA structure is affected severely by the crystal packing environment rather than by the base sequence.
 ==About this Structure==
-D 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=138D OCA].
+D 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=138D OCA].
 ==Reference==
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 [[Category: double helix]]
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