223d
From Proteopedia
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|PDB= 223d |SIZE=350|CAPTION= <scene name='initialview01'>223d</scene>, resolution 1.700Å | |PDB= 223d |SIZE=350|CAPTION= <scene name='initialview01'>223d</scene>, resolution 1.700Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=C46:6H,8H-3,4-DIHYDROPYRIMIDO[4,5-C][1,2]OXAZIN-7-0NE(CYTIDINE)-5'-MONOPHOSPHATE'>C46</scene>, <scene name='pdbligand=DC:2'-DEOXYCYTIDINE-5'-MONOPHOSPHATE'>DC</scene>, <scene name='pdbligand=DG:2'-DEOXYGUANOSINE-5'-MONOPHOSPHATE'>DG</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=223d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=223d OCA], [http://www.ebi.ac.uk/pdbsum/223d PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=223d RCSB]</span> | ||
}} | }} | ||
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[[Category: z-dna]] | [[Category: z-dna]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 01:44:32 2008'' |
Revision as of 22:44, 30 March 2008
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| , resolution 1.700Å | |||||||
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| Ligands: | , , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
DIRECT OBSERVATION OF TWO BASE-PAIRING MODES OF A CYTOSINE-THYMINE ANALOGUE WITH GUANINE IN A DNA Z-FORM DUPLEX: SIGNIFICANCE FOR BASE ANALOGUE MUTAGENESIS
Overview
The pyrimidine nucleobase analogue 6H,8H-3,4-dihydropyrimido[4,5-c]- [1,2]oxazin-7-one (P) is a mimic both of cytosine and thymine, since it can form stable hydrogen-bonded base-pairs with either guanine or adenine. To investigate the geometric properties of pairing with guanine in a DNA double helix, the structure of d(CGCGPG)2 has been determined by single crystal X-ray analysis. The oligonucleotide crystallised as a left-handed Z-DNA duplex in the orthorhombic space group P2(1)2(1)2(1) with cell dimensions a = 18.23 A, b = 30.63 A, c = 43.78 A. Refinement using NUCLSQ with 51 water molecules included in the final model converged at R = 0.179 (Rw = 0.159) for 2798 reflections (F > 2 sigma (F)) in the range 8 A to 1.7 A. Remarkably, the two P.G pairs in the hexamer duplex are different: Watson-Crick and wobble types separately illustrate both cytosine-like and thymine-like behaviour. The result suggests that mutagenesis experiments involving P and other analogues which display pronounced base-pairing ambivalence can be used to examine the structural basis of substrate discrimination by polymerases that is essential to accurate genetic replication.
About this Structure
223D is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Direct observation of two base-pairing modes of a cytosine-thymine analogue with guanine in a DNA Z-form duplex: significance for base analogue mutagenesis., Moore MH, Van Meervelt L, Salisbury SA, Lin PK, Brown DM, J Mol Biol. 1995 Sep 1;251(5):665-73. PMID:7666418
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