244d | pdb_0000244d
THE HIGH-RESOLUTION CRYSTAL STRUCTURE OF A PARALLEL-STRANDED GUANINE TETRAPLEX
Overview
Repeat tracts of guanine bases found in DNA and RNA can form tetraplex structures in the presence of a variety of monovalent cations. Evidence suggests that guanine tetraplexes assume important functions within chromosomal telomeres, immunoglobulin switch regions, and the human immunodeficiency virus genome. The structure of a parallel-stranded tetraplex formed by the hexanucleotide d(TG4T) and stabilized by sodium cations was determined by x-ray crystallography to 1.2 angstroms resolution. Sharply resolved sodium cations were found between and within planes of hydrogen-bonded guanine quartets, and an ordered groove hydration was observed. Distinct intra- and intermolecular stacking arrangements were adopted by the guanine quartets. Thymine bases were exclusively involved in making extensive lattice contacts.
About this Structure
Full crystallographic information is available from OCA.
Reference
The high-resolution crystal structure of a parallel-stranded guanine tetraplex., Laughlan G, Murchie AI, Norman DG, Moore MH, Moody PC, Lilley DM, Luisi B, Science. 1994 Jul 22;265(5171):520-4. PMID:8036494 Page seeded by OCA on Sat May 3 18:22:27 2008
