Publication Abstract from PubMed
The crystal structure of the tetragonal form of d(gcGAAAgc) has been revised and reasonably refined including the disordered residues. The two DNA strands form a base-intercalated duplex, and the four duplexes are assembled according to the crystallographic 222 symmetry to form an octaplex. In the central region, the eight strands are associated by I-motif of double A-quartets. Furthermore, eight hydrated-magnesium cations link the four duplexes to support the octaplex formation. Based on these structural features, a proposal that folding of d(GAAA)n, found in the non-coding region of genomes, into an octaplex can induce slippage during replication to facilitate length polymorphism is presented.
DNA octaplex formation with an I-motif of water-mediated A-quartets: reinterpretation of the crystal structure of d(GCGAAAGC).,Sato Y, Mitomi K, Sunami T, Kondo J, Takenaka A J Biochem. 2006 Dec;140(6):759-62. Epub 2006 Oct 24. PMID:17062599[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
