Crystal structure at 1.5-A resolution of d(CGCICICG), an octanucleotide containing inosine, and its comparison with d(CGCG) and d(CGCGCG) structures.
Kumar, V.D., Harrison, R.W., Andrews, L.C., Weber, I.T.(1992) Biochemistry 31: 1541-1550
- PubMed: 1737011
- DOI: https://doi.org/10.1021/bi00120a035
- Primary Citation of Related Structures:
1D53 - PubMed Abstract:
The octadeoxyribonucleotide d(CGCICICG) has been crystallized in space group P(6)5(22) with unit cell dimensions of a = b = 31.0 A and c = 43.7 A, and X-ray diffraction data have been collected to 1.5-A resolution. Precession photographs and the self-Patterson function indicate that 12 base pairs of Z-conformation DNA stack along the c-axis, and the double helices pack in a hexagonal array similar to that seen in other crystals of Z-DNA. The structure has been solved by both Patterson deconvolution and molecular replacement methods and refined in space group P(6)5 to an R factor of 0.225 using 2503 unique reflections greater than 3.0 sigma (F). Comparison of the molecules within the hexagonal lattice with highly refined crystal structures of other Z-DNA reveals only minor conformational differences, most notably in the pucker of the deoxyribose of the purine residues. The DNA has multiple occupancy of C:I and C:G base pairs, and C:I base pairs adopt a conformation similar to that of C:G base pairs.
Organizational Affiliation:
National Cancer Institute, Frederick Cancer Research and Development Center, Maryland 21702-1201.