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1d93
From Proteopedia
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STRUCTURAL VARIATION IN D(CTCTAGAG). IMPLICATIONS FOR PROTEIN-DNA INTERACTIONS
Overview
Single-crystal X-ray diffraction techniques have been used to characterize, the structure of the self-complementary DNA oligomer d(CTCTAGAG). The, structure was refined to an R factor of 14.7% using data to 2.15-A, resolution. The tetragonal unit cell, space group P4(3)2(1)2, has, dimensions a = 42.53 and c = 24.33 A. The asymmetric unit consists of a, single strand or four base pairs. Two strands, related by a, crystallographic dyad axis, coil about each other to form a right-handed, duplex. This octamer duplex has a mean helix rotation of 32 degrees, 11.3, base pairs per turn, an average rise of 3.1 A, C3'-endo furanose, conformations, a shallow minor groove, and a deep major groove. Such, averaged parameters suggest classification of the octamer as a member of, the A-DNA family. However, the global parameters tend to mask variations, in conformational parameters observed at the level of the base pairs. In, particular, the central TpA (= TpA) step displays extensive interstrand, purine-purine overlap and an unusual sugar-phosphate backbone, conformation. These structural features may be directly related to certain, sequence-specific protein-DNA interactions involving nucleases and, repressors.
About this Structure
1D93 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Structural variation in d(CTCTAGAG). Implications for protein-DNA interactions., Hunter WN, D'Estaintot BL, Kennard O, Biochemistry. 1989 Mar 21;28(6):2444-51. PMID:2730875
Page seeded by OCA on Sun Nov 25 02:47:34 2007
