Structure of the fully modified left-handed cyclohexene nucleic acid sequence GTGTACAC.
CeNA oligonucleotides consist of a phosphorylated backbone where the deoxyribose sugars are replaced by cyclohexene moieties. The X-ray structure determination and analysis of a fully modified octamer sequence GTGTACAC, which is the first crystal structure of a carbocyclic-based nucleic acid, is presented. This particular sequence was built with left-handed building blocks and crystallizes as a left-handed double helix. The helix can be characterized as belonging to the (mirrored) A-type family. Crystallographic data were processed up to 1.53 A, and the octamer sequence crystallizes in the space group R32. The sugar puckering is found to adopt the 3H2 half-chair conformation which mimics the C3'-endo conformation of the ribose sugar. The double helices stack on top of each other to form continuous helices, and static disorder is observed due to this end-to-end stacking.
Robeyns
Koen
K
Katholieke Universiteit Leuven, Department of Chemistry, Biomolecular Architecture and BioMacS, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
Herdewijn
Piet
P
Van Meervelt
Luc
L
D001483:Base Sequence; D018360:Crystallography, X-Ray; D053138:Cyclohexenes / Q000737:chemistry*; D003855:Deoxyribose / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry*
D053138:Cyclohexenes; D009841:Oligonucleotides; C052568:cyclohexene; D003855:Deoxyribose