From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:161d.jpg|left|200px]] | + | {{Seed}} |
| | + | [[Image:161d.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_161d| PDB=161d | SCENE= }} | | {{STRUCTURE_161d| PDB=161d | SCENE= }} |
| | | | |
| - | '''A SINGLE 2'-HYDROXYL GROUP CONVERTS B-DNA TO A-DNA: CRYSTAL STRUCTURE OF THE DNA-RNA CHIMERIC DECAMER DUPLEX D(CCGGC)R(G)D(CCGG) WITH A NOVEL INTERMOLECULAR G.C BASE-PAIRED QUADRUPLET'''
| + | ===A SINGLE 2'-HYDROXYL GROUP CONVERTS B-DNA TO A-DNA: CRYSTAL STRUCTURE OF THE DNA-RNA CHIMERIC DECAMER DUPLEX D(CCGGC)R(G)D(CCGG) WITH A NOVEL INTERMOLECULAR G.C BASE-PAIRED QUADRUPLET=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | We have found that the introduction of a single 2'-hydroxyl group on the sugar-phosphate backbone of the B-DNA decamer d(CCGGCGCCGG) transforms it to A-DNA. Thus, for the first time the X-ray structures of the same sequence have been observed in both the A and B-DNA conformations, permitting a comparison. Crystals of the DNA-RNA chimeric decamer d(CCGGC)r(G)d(CCGG) belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions a = 25.63 A, b = 45.24 A and c = 47.99 A, and one decamer duplex in the asymmetric unit. The structure was solved by a rigid body search using the coordinates of the isomorphous structure d(CCCGGCCGGG) and refined to an R value of 0.136 using 2753 unique reflections at 1.9 A resolution. The final model contains 406 nucleotide atoms and 61 water molecules. The chimeric duplex exhibits typical A-DNA geometry, with all the sugars in the C(3')-endo puckering and the base-pairs inclined and displaced from the helix axis. The 2'-hydroxyl groups on rG6 and rG16 protrude into the minor groove surface and form different types of hydrogen bonds; that on strand 1 forms an intermolecular hydrogen bond with the furanose ring O(4') of a symmetry-related C1 residue, while that on strand 2 is involved in two water bridges. Crystal packing forces the G4-G17 base-pair in the top half of the duplex to slide significantly into the minor groove compared to the corresponding G7-G14 base-pair in the bottom half, resulting in these base-pairs exhibiting different base stacking and intermolecular interactions. The base G4 of the G4-G17 base-pair forms an unorthodox base "triple", G4*(G10-C11), hydrogen-bonding through its minor groove sites N(2) and N(3) to the minor groove atoms N(2) and O(2) of both bases of the G10-C11 base-pair of a symmetry-related molecule. The base G10 of this triple in turn forms a second similar unorthodox base triple, G10*(G3*C18), with the adjacent base-pair G3-C18 of the duplex, thus G10 is involved in a double triple. On the other hand, in the bottom half of the duplex, the C7-G14 base-pair is involved only in a single similar unorthodox base triple with G20, (C7-G14)*G20, while the adjacent base-pair rG6-C15 is involved in a novel quadruple with C1-G20, (rG6-C15) *(C1-G20), where the latter base-pairs are hydrogen-bonded to each other via the minor groove sites G(N(2))...C(O(2)).(ABSTRACT TRUNCATED AT 400 WORDS)
| + | The line below this paragraph, {{ABSTRACT_PUBMED_7508984}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 7508984 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_7508984}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 25: |
Line 29: |
| | [[Category: A-dna/rna]] | | [[Category: A-dna/rna]] |
| | [[Category: Double helix]] | | [[Category: Double helix]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 09:31:53 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jun 30 15:33:28 2008'' |
Revision as of 12:33, 30 June 2008
Template:STRUCTURE 161d
A SINGLE 2'-HYDROXYL GROUP CONVERTS B-DNA TO A-DNA: CRYSTAL STRUCTURE OF THE DNA-RNA CHIMERIC DECAMER DUPLEX D(CCGGC)R(G)D(CCGG) WITH A NOVEL INTERMOLECULAR G.C BASE-PAIRED QUADRUPLET
Template:ABSTRACT PUBMED 7508984
About this Structure
Full crystallographic information is available from OCA.
Reference
A single 2'-hydroxyl group converts B-DNA to A-DNA. Crystal structure of the DNA-RNA chimeric decamer duplex d(CCGGC)r(G)d(CCGG) with a novel intermolecular G-C base-paired quadruplet., Ban C, Ramakrishnan B, Sundaralingam M, J Mol Biol. 1994 Feb 11;236(1):275-85. PMID:7508984
Page seeded by OCA on Mon Jun 30 15:33:28 2008
