title: A crystallographic map of the transition from B-DNA to A-DNA.
abstract: The transition between B- and A-DNA was first observed nearly 50 years ago. We have now mapped this transformation through a set of single-crystal structures of the sequence d(GGCGCC)2, with various intermediates being trapped by methylating or brominating the cytosine bases. The resulting pathway progresses through 13 conformational steps, with a composite structure that pairs A-nucleotides with complementary B-nucleotides serving as a distinct transition intermediate. The details of each step in the conversion of B- to A-DNA are thus revealed at the atomic level, placing intermediates for this and other sequences in the context of a common pathway.
authors.affiliation: Department of Biochemistry and Biophysics, ALS 2011, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Vargason
authors.forename: K
authors.initials: K
authors.lastname: Henderson
authors.forename: P S
authors.initials: PS
authors.lastname: Ho
mesh_terms: D001483:Base Sequence; D018360:Crystallography, X-Ray / Q000379:methods; D004247:DNA / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D009838:Oligodeoxyribonucleotides; D004247:DNA