2dz7
From Proteopedia
DNA Octaplex Formation with an I-Motif of A-Quartets: The Revised Crystal Structure of d(GCGAAAGC)
Overview
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.
About this Structure
Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Sun May 4 01:38:47 2008
Categories: Kondo, J. | Mitomi, K. | Sato, Y. | Sumani, T. | Takenaka, A. | A-quartet | Dna octaplex | Non-coding dna | Vntr
