This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1d93
From Proteopedia
| |||||||
| , resolution 2.150Å | |||||||
|---|---|---|---|---|---|---|---|
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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 Thu Mar 20 10:34:42 2008
