5ana: Difference between revisions
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[[Image:5ana.gif|left|200px]] | [[Image:5ana.gif|left|200px]] | ||
'''THE CRYSTAL STRUCTURE OF D(GTACGTAC) AT 2.25 ANGSTROMS RESOLUTION. ARE THE A-DNA'S ALWAYS UNWOUND APPROXIMATELY 10 DEGREES AT THE C-G STEPS''' | {{Structure | ||
|PDB= 5ana |SIZE=350|CAPTION= <scene name='initialview01'>5ana</scene>, resolution 2.250Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''THE CRYSTAL STRUCTURE OF D(GTACGTAC) AT 2.25 ANGSTROMS RESOLUTION. ARE THE A-DNA'S ALWAYS UNWOUND APPROXIMATELY 10 DEGREES AT THE C-G STEPS''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
5ANA is a [ | 5ANA 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=5ANA OCA]. | ||
==Reference== | ==Reference== | ||
The crystal structure of d(GTACGTAC) at 2.25 A resolution: are the A-DNA's always unwound approximately 10 degrees at the C-G steps?, Takusagawa F, J Biomol Struct Dyn. 1990 Feb;7(4):795-809. PMID:[http:// | The crystal structure of d(GTACGTAC) at 2.25 A resolution: are the A-DNA's always unwound approximately 10 degrees at the C-G steps?, Takusagawa F, J Biomol Struct Dyn. 1990 Feb;7(4):795-809. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/2310515 2310515] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Takusagawa, F.]] | [[Category: Takusagawa, F.]] | ||
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[[Category: double helix]] | [[Category: double helix]] | ||
''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 19:11:31 2008'' | ||
Revision as of 17:11, 20 March 2008
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| 5ana, resolution 2.250Å | |||||||||||||
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| Ligands: | MG | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
THE CRYSTAL STRUCTURE OF D(GTACGTAC) AT 2.25 ANGSTROMS RESOLUTION. ARE THE A-DNA'S ALWAYS UNWOUND APPROXIMATELY 10 DEGREES AT THE C-G STEPS
Overview
The structure of the self-complementary octamer d(GTACGTAC) has been analyzed by a single crystal X-ray diffraction method at 2.25 A resolution. The crystallographic R factor was 0.184 for all 1233 reflections at this resolution. In spite of the alternating purine-pyrimidine sequence, d(GTACGTAC) adopts the A-form conformation rather than the left-handed Z-form. The average helix twist and the mean rise per base pair are 32.1 degrees and 3.18 A, respectively. The d(GTACGTAC) helix is characterized by a wide open major groove and small base-pair tilt (9.7 degrees). The partial unwinding of the helix is observed only at the central pyrimidine-purine C-G step, but not at the other pyrimidine-purine T-A steps. Based on this study and six other X-ray studies, we propose a hypothesis that the A-DNA's are always unwound approximately 10 degrees at the C-G steps. Significant differences in base-pair stacking modes are seen between the purine-pyrimidine step and the pyrimidine-purine step. All deoxyribose rings adopt the C3'-endo conformation. All backbone torsion angles fall into the range expected for the A-DNA form, except for the nucleotide G5, whose alpha and gamma torsion angles adopt the trans, trans conformation instead of the common gauche-, gauche+ conformation.
About this Structure
5ANA is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
The crystal structure of d(GTACGTAC) at 2.25 A resolution: are the A-DNA's always unwound approximately 10 degrees at the C-G steps?, Takusagawa F, J Biomol Struct Dyn. 1990 Feb;7(4):795-809. PMID:2310515
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