Publication Abstract from PubMed
The base analogue N4-methoxycytosine (mo4C) is ambivalent in its hydrogen-bonding potential, since it forms stable base-pairs with both adenine and guanine in oligomer duplexes. To investigate the base-pair geometry, the structure of d(CGCGmo4CG) has been determined by single-crystal X-ray diffraction techniques. The d(CGCGmo4CG)2 crystallized in a left-handed double helical structure (Z-type). Refinement using 2559 reflections between 10 and 1.7 A converged with a final R = 0.181 (Rw = 0.130) including 68 solvent molecules. The orthorhombic crystals are in the space group P2(1)2(1)2(1), with cell dimensions a = 18.17 A, b = 30.36 A, c = 43.93 A. The mo4C.G base-pair is of the wobble type, with mo4C in the imino form, and the methoxy group in the syn configuration.
Molecular and crystal structure of d(CGCGmo4CG): N4-methoxycytosine.guanine base-pairs in Z-DNA.,Van Meervelt L, Moore MH, Lin PK, Brown DM, Kennard O J Mol Biol. 1990 Dec 5;216(3):773-81. PMID:2258939[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
