1da2
From Proteopedia
MOLECULAR AND CRYSTAL STRUCTURE OF D(CGCGMO4CG): N4-METHOXYCYTOSINE/GUANINE BASE-PAIRS IN Z-DNA
Overview
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.
About this Structure
Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Fri May 2 13:37:10 2008
