1UB8:
reference: Structures of d(GCGAAGC) and d(GCGAAAGC) (tetragonal form): a switching of partners of the sheared G.A pairs to form a functional G.AxA.G crossing., Sunami T, Kondo J, Hirao I, Watanabe K, Miura KI, Takenaka A, Acta Crystallogr D Biol Crystallogr 2004 Mar;60(Pt 3):422-31. Epub 2004, Feb 25. PMID: 14993665

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