117D

CRYSTAL AND MOLECULAR STRUCTURE OF THE ALTERNATING DODECAMER D(GCGTACGTACGC) IN THE A-DNA FORM: COMPARISON WITH THE ISOMORPHOUS NON-ALTERNATING DODECAMER D(CCGTACGTACGG)

Summary for 117D

• Entry DOI: 10.2210/pdb117d/pdb
• Descriptor: DNA (5'-D(*GP*CP*GP*TP*AP*CP*GP*TP*AP*CP*GP*C)-3') (2 entities in total)
• Functional Keywords: a-dna, double helix, dna
• Total number of polymer chains: 1
• Total formula weight: 3663.39

Authors

Bingman, C.A.,Jain, S.,Zon, G.,Sundaralingam, M. (deposition date: 1993-02-10, release date: 1993-04-15, Last modification date: 2023-03-22)

Primary citation

Bingman, C.A.,Jain, S.,Zon, G.,Sundaralingam, M.
Crystal and molecular structure of the alternating dodecamer d(GCGTACGTACGC) in the A-DNA form: comparison with the isomorphous non-alternating dodecamer d(CCGTACGTACGG).
Nucleic Acids Res., 20:6637-6647, 1992

PubMed Abstract: The crystal structure of the alternating dodecamer d(GCGTACGTACGC) (5'-GC) has been determined to a resolution of 2.55A using oscillation film data. The crystals belong to space group P6(1) 22, a = b = 46.2A, c = 71.5A with one strand in the asymmetric unit, and are isomorphous with a previously described non-alternating dodecamer, d(CCGTACGTACGG) (5'-CC). Refinement by X-PLOR/NUCLSQ gave a final R factor of 14.2% for 1089 observations. The molecule adopts the A-DNA form. The interchange of the terminal base pairs in the two dodecamers results in differences in the intermolecular contacts and may account for the differences in the bending. This dodecamer shows an axial deflection of 30 degrees, in the direction of the major groove compared to 20 degrees in 5'-CC and may be a consequence of additional contacts generated in 5'-GC by the interchange of end base pairs. The high helical axis deflection appreciably influences the local helical parameters. The molecule exhibits relatively high inclination angles, and has a narrow major groove. The helical parameters when described relative to the dyad-related hexamer halves of the molecule give more reasonable values. The crystal packing, local helical parameters, torsion angles, and hydration are described and also compared with the non-alternating 5'-CC dodecamer.

PubMed: 1480485
DOI: 10.1093/nar/20.24.6637

Experimental method

X-RAY DIFFRACTION (2.55 Å)