1N1O

Crystal Structure of a B-form DNA Duplex Containing (L)-alpha-threofuranosyl (3'-2') Nucleosides: A Four-Carbon Sugar is Easily Accommodated into the Backbone of DNA

Summary for 1N1O

• Entry DOI: 10.2210/pdb1n1o/pdb
• Descriptor: 5'-D(*CP*GP*CP*GP*AP*AP*(TFT)P*TP*CP*GP*CP*G)-3', MAGNESIUM ION (3 entities in total)
• Functional Keywords: b-dna, hydrogen bonding, nucleic acid etiology, tetrose, four-carbon sugar, nucleic acid analogue, dna
• Total number of polymer chains: 2
• Total formula weight: 7323.04

Authors

Wilds, C.J.,Wawrzak, Z.,Krishnamurthy, R.,Eschenmoser, A.,Egli, M. (deposition date: 2002-10-18, release date: 2002-11-15, Last modification date: 2024-04-03)

Primary citation

Wilds, C.J.,Wawrzak, Z.,Krishnamurthy, R.,Eschenmoser, A.,Egli, M.
Crystal Structure of a B-Form DNA Duplex Containing (L)-alpha-Threofuranosyl (3'-->2') Nucleosides: A Four-Carbon Sugar Is Easily Accommodated into the Backbone of DNA
J.Am.Chem.Soc., 124:13716-13721, 2002

PubMed Abstract: (L)-alpha-Threofuranosyl-(3'-->2')-oligonucleotides (TNA) containing vicinally connected phosphodiester linkages undergo informational base pairing in an antiparallel strand orientation and are capable of cross-pairing with RNA and DNA. TNA is derived from a sugar containing only four carbon atoms and is one of the simplest potentially natural nucleic acid alternatives investigated thus far in the context of a chemical etiology of nucleic acid structure. Compared to DNA and RNA that contain six covalent bonds per repeating nucleotide unit, TNA contains only five. We have determined the atomic-resolution crystal structure of the B-form DNA duplex [d(CGCGAA)Td(TCGCG)](2) containing a single (L)-alpha-threofuranosyl thymine (T) per strand. In the modified duplex base stacking interactions are practically unchanged relative to the reference DNA structure. The orientations of the backbone at the TNA incorporation sites are slightly altered in order to accommodate fewer atoms and covalent bonds. The conformation of the threose is C4'-exo with the 2'- and 3'-substituents assuming quasi-diaxial orientation.

PubMed: 12431101
DOI: 10.1021/ja0207807

Experimental method

X-RAY DIFFRACTION (1.2 Å)