Download MendeleyX-ray analyses of d(GCGAXAGC) containing G and T at X: the base-intercalated duplex is still stable even in point mutants at the fifth residue.
Kondo, J., Umeda, S.I., Fujita, K., Sunami, T., Takenaka, A.(2004) J Synchrotron Radiat 11: 117-120
- PubMed: 14646150
- DOI: https://doi.org/10.1107/s0909049503023562
- Primary Citation of Related Structures:
1UHX, 1UHY - PubMed Abstract:
DNA fragments containing the sequence d(GCGAAAGC) prefer to adopt a base-intercalated (zipper-like) duplex in the crystalline state. To investigate effects of point mutation at the 5th residue on the structure, two crystal structures of d(GCGAGAGC) and d(GCGATAGC) have been determined by X-ray crystallography. In the respective crystals, the two octamers related by a crystallographic two-fold symmetry are aligned in an anti-parallel fashion and associated to each other to form a duplex, suggesting that the base-intercalated duplex is stable even when the 5th residue is mutated with other bases. The sheared G3:A6 pair formation makes the two phosphate backbones closer and facilitates formation of the A-X*-X-A* base-intercalated motif. The three duplexes are assembled around the three-fold axis, and their 3rd and 4th residues are bound to the hexamine cobalt chloride. The central 5th residues are bound to another cation.
Organizational Affiliation:
Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan.
